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Remove the unneeded semicolon after curly braces.
Signed-off-by: Shaomin Deng <dengshaomin@cdjrlc.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Message-Id: <20221105153135.5975-1-dengshaomin@cdjrlc.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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We should use this replace thie.
Signed-off-by: Deming Wang <wangdeming@inspur.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Message-Id: <20230206091815.1687-1-wangdeming@inspur.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The pointer cb_sb_start is being initialized with a value that is never
read, it is being re-assigned the same value later on when it is first
being used. The initialization is redundant and can be removed.
Cleans up clang scan build warning:
fs/ntfs/compress.c:164:6: warning: Value stored to 'cb_sb_start' during its initialization is never read [deadcode.DeadStores]
u8 *cb_sb_start = cb; /* Beginning of the current sb in the cb. */
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Message-Id: <20230418153607.3125704-1-colin.i.king@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Various distributions are adding or are in the process of adding support
for system extensions and in the future configuration extensions through
various tools. A more detailed explanation on system and configuration
extensions can be found on the manpage which is listed below at [1].
System extension images may – dynamically at runtime — extend the /usr/
and /opt/ directory hierarchies with additional files. This is
particularly useful on immutable system images where a /usr/ and/or
/opt/ hierarchy residing on a read-only file system shall be extended
temporarily at runtime without making any persistent modifications.
When one or more system extension images are activated, their /usr/ and
/opt/ hierarchies are combined via overlayfs with the same hierarchies
of the host OS, and the host /usr/ and /opt/ overmounted with it
("merging"). When they are deactivated, the mount point is disassembled
— again revealing the unmodified original host version of the hierarchy
("unmerging"). Merging thus makes the extension's resources suddenly
appear below the /usr/ and /opt/ hierarchies as if they were included in
the base OS image itself. Unmerging makes them disappear again, leaving
in place only the files that were shipped with the base OS image itself.
System configuration images are similar but operate on directories
containing system or service configuration.
On nearly all modern distributions mount propagation plays a crucial
role and the rootfs of the OS is a shared mount in a peer group (usually
with peer group id 1):
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/ / ext4 shared:1 29 1
On such systems all services and containers run in a separate mount
namespace and are pivot_root()ed into their rootfs. A separate mount
namespace is almost always used as it is the minimal isolation mechanism
services have. But usually they are even much more isolated up to the
point where they almost become indistinguishable from containers.
Mount propagation again plays a crucial role here. The rootfs of all
these services is a slave mount to the peer group of the host rootfs.
This is done so the service will receive mount propagation events from
the host when certain files or directories are updated.
In addition, the rootfs of each service, container, and sandbox is also
a shared mount in its separate peer group:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/ / ext4 shared:24 master:1 71 47
For people not too familiar with mount propagation, the master:1 means
that this is a slave mount to peer group 1. Which as one can see is the
host rootfs as indicated by shared:1 above. The shared:24 indicates that
the service rootfs is a shared mount in a separate peer group with peer
group id 24.
A service may run other services. Such nested services will also have a
rootfs mount that is a slave to the peer group of the outer service
rootfs mount.
For containers things are just slighly different. A container's rootfs
isn't a slave to the service's or host rootfs' peer group. The rootfs
mount of a container is simply a shared mount in its own peer group:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/home/ubuntu/debian-tree / ext4 shared:99 61 60
So whereas services are isolated OS components a container is treated
like a separate world and mount propagation into it is restricted to a
single well known mount that is a slave to the peer group of the shared
mount /run on the host:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/propagate/debian-tree /run/host/incoming tmpfs master:5 71 68
Here, the master:5 indicates that this mount is a slave to the peer
group with peer group id 5. This allows to propagate mounts into the
container and served as a workaround for not being able to insert mounts
into mount namespaces directly. But the new mount api does support
inserting mounts directly. For the interested reader the blogpost in [2]
might be worth reading where I explain the old and the new approach to
inserting mounts into mount namespaces.
Containers of course, can themselves be run as services. They often run
full systems themselves which means they again run services and
containers with the exact same propagation settings explained above.
The whole system is designed so that it can be easily updated, including
all services in various fine-grained ways without having to enter every
single service's mount namespace which would be prohibitively expensive.
The mount propagation layout has been carefully chosen so it is possible
to propagate updates for system extensions and configurations from the
host into all services.
The simplest model to update the whole system is to mount on top of
/usr, /opt, or /etc on the host. The new mount on /usr, /opt, or /etc
will then propagate into every service. This works cleanly the first
time. However, when the system is updated multiple times it becomes
necessary to unmount the first update on /opt, /usr, /etc and then
propagate the new update. But this means, there's an interval where the
old base system is accessible. This has to be avoided to protect against
downgrade attacks.
The vfs already exposes a mechanism to userspace whereby mounts can be
mounted beneath an existing mount. Such mounts are internally referred
to as "tucked". The patch series exposes the ability to mount beneath a
top mount through the new MOVE_MOUNT_BENEATH flag for the move_mount()
system call. This allows userspace to seamlessly upgrade mounts. After
this series the only thing that will have changed is that mounting
beneath an existing mount can be done explicitly instead of just
implicitly.
Today, there are two scenarios where a mount can be mounted beneath an
existing mount instead of on top of it:
(1) When a service or container is started in a new mount namespace and
pivot_root()s into its new rootfs. The way this is done is by
mounting the new rootfs beneath the old rootfs:
fd_newroot = open("/var/lib/machines/fedora", ...);
fd_oldroot = open("/", ...);
fchdir(fd_newroot);
pivot_root(".", ".");
After the pivot_root(".", ".") call the new rootfs is mounted
beneath the old rootfs which can then be unmounted to reveal the
underlying mount:
fchdir(fd_oldroot);
umount2(".", MNT_DETACH);
Since pivot_root() moves the caller into a new rootfs no mounts must
be propagated out of the new rootfs as a consequence of the
pivot_root() call. Thus, the mounts cannot be shared.
(2) When a mount is propagated to a mount that already has another mount
mounted on the same dentry.
The easiest example for this is to create a new mount namespace. The
following commands will create a mount namespace where the rootfs
mount / will be a slave to the peer group of the host rootfs /
mount's peer group. IOW, it will receive propagation from the host:
mount --make-shared /
unshare --mount --propagation=slave
Now a new mount on the /mnt dentry in that mount namespace is
created. (As it can be confusing it should be spelled out that the
tmpfs mount on the /mnt dentry that was just created doesn't
propagate back to the host because the rootfs mount / of the mount
namespace isn't a peer of the host rootfs.):
mount -t tmpfs tmpfs /mnt
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt tmpfs tmpfs
Now another terminal in the host mount namespace can observe that
the mount indeed hasn't propagated back to into the host mount
namespace. A new mount can now be created on top of the /mnt dentry
with the rootfs mount / as its parent:
mount --bind /opt /mnt
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt /dev/sda2[/opt] ext4 shared:1
The mount namespace that was created earlier can now observe that
the bind mount created on the host has propagated into it:
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt /dev/sda2[/opt] ext4 master:1
└─/mnt tmpfs tmpfs
But instead of having been mounted on top of the tmpfs mount at the
/mnt dentry the /opt mount has been mounted on top of the rootfs
mount at the /mnt dentry. And the tmpfs mount has been remounted on
top of the propagated /opt mount at the /opt dentry. So in other
words, the propagated mount has been mounted beneath the preexisting
mount in that mount namespace.
Mount namespaces make this easy to illustrate but it's also easy to
mount beneath an existing mount in the same mount namespace
(The following example assumes a shared rootfs mount / with peer
group id 1):
mount --bind /opt /opt
TARGET SOURCE FSTYPE MNT_ID PARENT_ID PROPAGATION
└─/opt /dev/sda2[/opt] ext4 188 29 shared:1
If another mount is mounted on top of the /opt mount at the /opt
dentry:
mount --bind /tmp /opt
The following clunky mount tree will result:
TARGET SOURCE FSTYPE MNT_ID PARENT_ID PROPAGATION
└─/opt /dev/sda2[/tmp] ext4 405 29 shared:1
└─/opt /dev/sda2[/opt] ext4 188 405 shared:1
└─/opt /dev/sda2[/tmp] ext4 404 188 shared:1
The /tmp mount is mounted beneath the /opt mount and another copy is
mounted on top of the /opt mount. This happens because the rootfs /
and the /opt mount are shared mounts in the same peer group.
When the new /tmp mount is supposed to be mounted at the /opt dentry
then the /tmp mount first propagates to the root mount at the /opt
dentry. But there already is the /opt mount mounted at the /opt
dentry. So the old /opt mount at the /opt dentry will be mounted on
top of the new /tmp mount at the /tmp dentry, i.e. @opt->mnt_parent
is @tmp and @opt->mnt_mountpoint is /tmp (Note that @opt->mnt_root
is /opt which is what shows up as /opt under SOURCE). So again, a
mount will be mounted beneath a preexisting mount.
(Fwiw, a few iterations of mount --bind /opt /opt in a loop on a
shared rootfs is a good example of what could be referred to as
mount explosion.)
The main point is that such mounts allows userspace to umount a top
mount and reveal an underlying mount. So for example, umounting the
tmpfs mount on /mnt that was created in example (1) using mount
namespaces reveals the /opt mount which was mounted beneath it.
In (2) where a mount was mounted beneath the top mount in the same mount
namespace unmounting the top mount would unmount both the top mount and
the mount beneath. In the process the original mount would be remounted
on top of the rootfs mount / at the /opt dentry again.
This again, is a result of mount propagation only this time it's umount
propagation. However, this can be avoided by simply making the parent
mount / of the @opt mount a private or slave mount. Then the top mount
and the original mount can be unmounted to reveal the mount beneath.
These two examples are fairly arcane and are merely added to make it
clear how mount propagation has effects on current and future features.
More common use-cases will just be things like:
mount -t btrfs /dev/sdA /mnt
mount -t xfs /dev/sdB --beneath /mnt
umount /mnt
after which we'll have updated from a btrfs filesystem to a xfs
filesystem without ever revealing the underlying mountpoint.
The crux is that the proposed mechanism already exists and that it is so
powerful as to cover cases where mounts are supposed to be updated with
new versions. Crucially, it offers an important flexibility. Namely that
updates to a system may either be forced or can be delayed and the
umount of the top mount be left to a service if it is a cooperative one.
This adds a new flag to move_mount() that allows to explicitly move a
beneath the top mount adhering to the following semantics:
* Mounts cannot be mounted beneath the rootfs. This restriction
encompasses the rootfs but also chroots via chroot() and pivot_root().
To mount a mount beneath the rootfs or a chroot, pivot_root() can be
used as illustrated above.
* The source mount must be a private mount to force the kernel to
allocate a new, unused peer group id. This isn't a required
restriction but a voluntary one. It avoids repeating a semantical
quirk that already exists today. If bind mounts which already have a
peer group id are inserted into mount trees that have the same peer
group id this can cause a lot of mount propagation events to be
generated (For example, consider running mount --bind /opt /opt in a
loop where the parent mount is a shared mount.).
* Avoid getting rid of the top mount in the kernel. Cooperative services
need to be able to unmount the top mount themselves.
This also avoids a good deal of additional complexity. The umount
would have to be propagated which would be another rather expensive
operation. So namespace_lock() and lock_mount_hash() would potentially
have to be held for a long time for both a mount and umount
propagation. That should be avoided.
* The path to mount beneath must be mounted and attached.
* The top mount and its parent must be in the caller's mount namespace
and the caller must be able to mount in that mount namespace.
* The caller must be able to unmount the top mount to prove that they
could reveal the underlying mount.
* The propagation tree is calculated based on the destination mount's
parent mount and the destination mount's mountpoint on the parent
mount. Of course, if the parent of the destination mount and the
destination mount are shared mounts in the same peer group and the
mountpoint of the new mount to be mounted is a subdir of their
->mnt_root then both will receive a mount of /opt. That's probably
easier to understand with an example. Assuming a standard shared
rootfs /:
mount --bind /opt /opt
mount --bind /tmp /opt
will cause the same mount tree as:
mount --bind /opt /opt
mount --beneath /tmp /opt
because both / and /opt are shared mounts/peers in the same peer
group and the /opt dentry is a subdirectory of both the parent's and
the child's ->mnt_root. If a mount tree like that is created it almost
always is an accident or abuse of mount propagation. Realistically
what most people probably mean in this scenarios is:
mount --bind /opt /opt
mount --make-private /opt
mount --make-shared /opt
This forces the allocation of a new separate peer group for the /opt
mount. Aferwards a mount --bind or mount --beneath actually makes
sense as the / and /opt mount belong to different peer groups. Before
that it's likely just confusion about what the user wanted to achieve.
* Refuse MOVE_MOUNT_BENEATH if:
(1) the @mnt_from has been overmounted in between path resolution and
acquiring @namespace_sem when locking @mnt_to. This avoids the
proliferation of shadow mounts.
(2) if @to_mnt is moved to a different mountpoint while acquiring
@namespace_sem to lock @to_mnt.
(3) if @to_mnt is unmounted while acquiring @namespace_sem to lock
@to_mnt.
(4) if the parent of the target mount propagates to the target mount
at the same mountpoint.
This would mean mounting @mnt_from on @mnt_to->mnt_parent and then
propagating a copy @c of @mnt_from onto @mnt_to. This defeats the
whole purpose of mounting @mnt_from beneath @mnt_to.
(5) if the parent mount @mnt_to->mnt_parent propagates to @mnt_from at
the same mountpoint.
If @mnt_to->mnt_parent propagates to @mnt_from this would mean
propagating a copy @c of @mnt_from on top of @mnt_from. Afterwards
@mnt_from would be mounted on top of @mnt_to->mnt_parent and
@mnt_to would be unmounted from @mnt->mnt_parent and remounted on
@mnt_from. But since @c is already mounted on @mnt_from, @mnt_to
would ultimately be remounted on top of @c. Afterwards, @mnt_from
would be covered by a copy @c of @mnt_from and @c would be covered
by @mnt_from itself. This defeats the whole purpose of mounting
@mnt_from beneath @mnt_to.
Cases (1) to (3) are required as they deal with races that would cause
bugs or unexpected behavior for users. Cases (4) and (5) refuse
semantical quirks that would not be a bug but would cause weird mount
trees to be created. While they can already be created via other means
(mount --bind /opt /opt x n) there's no reason to repeat past mistakes
in new features.
Link: https://man7.org/linux/man-pages/man8/systemd-sysext.8.html [1]
Link: https://brauner.io/2023/02/28/mounting-into-mount-namespaces.html [2]
Link: https://github.com/flatcar/sysext-bakery
Link: https://fedoraproject.org/wiki/Changes/Unified_Kernel_Support_Phase_1
Link: https://fedoraproject.org/wiki/Changes/Unified_Kernel_Support_Phase_2
Link: https://github.com/systemd/systemd/pull/26013
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v4-4-98f3d80d7eaa@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Currently, lock_mount() uses a goto to retry the lookup until it
succeeded in acquiring the namespace_lock() preventing the top mount
from being overmounted. While that's perfectly fine we want to lookup
the mountpoint on the parent of the top mount in later patches. So adapt
the code to make this easier to implement. Also, the for loop is
arguably a little cleaner and makes the code easier to follow. No
functional changes intended.
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v4-3-98f3d80d7eaa@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The comment on top of __lookup_mnt() states that it finds the first
mount implying that there could be multiple mounts mounted at the same
dentry with the same parent.
On older kernels "shadow mounts" could be created during mount
propagation. So if a mount @m in the destination propagation tree
already had a child mount @p mounted at @mp then any mount @n we
propagated to @m at the same @mp would be appended after the preexisting
mount @p in @mount_hashtable. This was a completely direct way of
creating shadow mounts.
That direct way is gone but there are still subtle ways to create shadow
mounts. For example, when attaching a source mnt @mnt to a shared mount.
The root of the source mnt @mnt might be overmounted by a mount @o after
we finished path lookup but before we acquired the namespace semaphore
to copy the source mount tree @mnt.
After we acquired the namespace lock @mnt is copied including @o
covering it. After we attach @mnt to a shared mount @dest_mnt we end up
propagation it to all it's peer and slaves @d. If @d already has a mount
@n mounted on top of it we tuck @mnt beneath @n. This means, we mount
@mnt at @d and mount @n on @mnt. Now we have both @o and @n mounted on
the same mountpoint at @mnt.
Explain this in the documentation as this is pretty subtle.
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v4-2-98f3d80d7eaa@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a small helper to check whether a path refers to the root of the
mount instead of open-coding this everywhere.
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v4-1-98f3d80d7eaa@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"Eight hotfixes. Four are cc:stable, the other four are for post-6.4
issues, or aren't considered suitable for backporting"
* tag 'mm-hotfixes-stable-2023-05-18-15-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
MAINTAINERS: Cleanup Arm Display IP maintainers
MAINTAINERS: repair pattern in DIALOG SEMICONDUCTOR DRIVERS
nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()
mm: fix zswap writeback race condition
mm: kfence: fix false positives on big endian
zsmalloc: move LRU update from zs_map_object() to zs_malloc()
mm: shrinkers: fix race condition on debugfs cleanup
maple_tree: make maple state reusable after mas_empty_area()
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When the MClientSnap reqeust's op is not CEPH_SNAP_OP_SPLIT the
request may still contain a list of 'split_realms', and we need
to skip it anyway. Or it will be parsed as a corrupt snaptrace.
Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/61200
Reported-by: Frank Schilder <frans@dtu.dk>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
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Smatch static checker warning:
fs/ceph/mds_client.c:3968 reconnect_caps_cb()
warn: missing error code here? '__get_cap_for_mds()' failed. 'err' = '0'
[ idryomov: Dan says that Smatch considers it intentional only if the
"ret = 0;" assignment is within 4 or 5 lines of the goto. ]
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
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During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). However, since
nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may
cause use-after-free read if inodes are left in "garbage_list" and
released by nilfs_dispose_list() at the end of nilfs_detach_log_writer().
Fix this issue by modifying nilfs_evict_inode() to only clear inode
without additional metadata changes that use nilfs_root if the file system
is degraded to read-only or the writer is detached.
Link: https://lkml.kernel.org/r/20230509152956.8313-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+78d4495558999f55d1da@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000099e5ac05fb1c3b85@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In cifs_oplock_break function we drop reference to a cfile at
the end of function, due to which close command goes on wire
after lease break acknowledgment even if file is already closed
by application but we had deferred the handle close.
If other client with limited file shareaccess waiting on lease
break ack proceeds operation on that file as soon as first client
sends ack, then we may encounter status sharing violation error
because of open handle.
Solution is to put reference to cfile(send close on wire if last ref)
and then send oplock acknowledgment to server.
Fixes: 9e31678fb403 ("SMB3: fix lease break timeout when multiple deferred close handles for the same file.")
Cc: stable@kernel.org
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Oplock break may occur for different file handle than the deferred
handle. Check for inode deferred closes list, if it's not empty then
close all the deferred handles of inode because we should not cache
handles if we dont have handle lease.
Eg: If openfilelist has one deferred file handle and another open file
handle from app for a same file, then on a lease break we choose the
first handle in openfile list. The first handle in list can be deferred
handle or actual open file handle from app. In case if it is actual open
handle then today, we don't close deferred handles if we lose handle lease
on a file. Problem with this is, later if app decides to close the existing
open handle then we still be caching deferred handles until deferred close
timeout. Leaving open handle may result in sharing violation when windows
client tries to open a file with limited file share access.
So we should check for deferred list of inode and walk through the list of
deferred files in inode and close all deferred files.
Fixes: 9e31678fb403 ("SMB3: fix lease break timeout when multiple deferred close handles for the same file.")
Cc: stable@kernel.org
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- A collection of minor bug fixes
* tag 'nfsd-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: Remove open coding of string copy
SUNRPC: Fix trace_svc_register() call site
SUNRPC: always free ctxt when freeing deferred request
SUNRPC: double free xprt_ctxt while still in use
SUNRPC: Fix error handling in svc_setup_socket()
SUNRPC: Fix encoding of accepted but unsuccessful RPC replies
lockd: define nlm_port_min,max with CONFIG_SYSCTL
nfsd: define exports_proc_ops with CONFIG_PROC_FS
SUNRPC: Avoid relying on crypto API to derive CBC-CTS output IV
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When writing EFI variables, one might get errors with no other message
on why it fails. Being able to see how much is used by EFI variables
helps analyzing such issues.
Since this is not a conventional filesystem, block size is intentionally
set to 1 instead of PAGE_SIZE.
x86 quirks of reserved size are taken into account; so that available
and free size can be different, further helping debugging space issues.
With this patch, one can see the remaining space in EFI variable storage
via efivarfs, like this:
$ df -h /sys/firmware/efi/efivars/
Filesystem Size Used Avail Use% Mounted on
efivarfs 176K 106K 66K 62% /sys/firmware/efi/efivars
Signed-off-by: Anisse Astier <an.astier@criteo.com>
[ardb: - rename efi_reserved_space() to efivar_reserved_space()
- whitespace/coding style tweaks]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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Commit f2620f166e2a caused the kernel to start emitting POSIX ACL xattrs
for NFSv4 inodes, which it doesn't support. The only other user of
generic_listxattr is HFS (classic) and it doesn't support POSIX ACLs
either.
Fixes: f2620f166e2a xattr: simplify listxattr helpers
Reported-by: Ondrej Valousek <ondrej.valousek.xm@renesas.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230516124655.82283-1-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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s390's struct statfs and struct statfs64 contain padding, which
field-by-field copying does not set. Initialize the respective structs
with zeros before filling them and copying them to userspace, like it's
already done for the compat versions of these structs.
Found by KMSAN.
[agordeev@linux.ibm.com: fixed typo in patch description]
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20230504144021.808932-2-iii@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
Our CI system caught a lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc7+ #1167 Not tainted
------------------------------------------------------
kswapd0/46 is trying to acquire lock:
ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120
but task is already holding lock:
ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0xa5/0xe0
kmem_cache_alloc+0x31/0x2c0
alloc_extent_state+0x1d/0xd0
__clear_extent_bit+0x2e0/0x4f0
try_release_extent_mapping+0x216/0x280
btrfs_release_folio+0x2e/0x90
invalidate_inode_pages2_range+0x397/0x470
btrfs_cleanup_dirty_bgs+0x9e/0x210
btrfs_cleanup_one_transaction+0x22/0x760
btrfs_commit_transaction+0x3b7/0x13a0
create_subvol+0x59b/0x970
btrfs_mksubvol+0x435/0x4f0
__btrfs_ioctl_snap_create+0x11e/0x1b0
btrfs_ioctl_snap_create_v2+0xbf/0x140
btrfs_ioctl+0xa45/0x28f0
__x64_sys_ioctl+0x88/0xc0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
-> #0 (sb_internal#2){++++}-{0:0}:
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
start_transaction+0x401/0x730
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
kthread+0xf0/0x120
ret_from_fork+0x29/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
*** DEADLOCK ***
3 locks held by kswapd0/46:
#0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
#1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290
#2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0
stack backtrace:
CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x58/0x90
check_noncircular+0xd6/0x100
? save_trace+0x3f/0x310
? add_lock_to_list+0x97/0x120
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
? btrfs_commit_inode_delayed_inode+0x5f/0x120
start_transaction+0x401/0x730
? btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
? lock_release+0x134/0x270
? __pfx_wake_bit_function+0x10/0x10
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
? __pfx_inode_lru_isolate+0x10/0x10
? __pfx_inode_lru_isolate+0x10/0x10
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
? __pfx_autoremove_wake_function+0x10/0x10
? __pfx_kswapd+0x10/0x10
kthread+0xf0/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x29/0x50
</TASK>
This happens because when we abort the transaction in the transaction
commit path we call invalidate_inode_pages2_range on our block group
cache inodes (if we have space cache v1) and any delalloc inodes we may
have. The plain invalidate_inode_pages2_range() call passes through
GFP_KERNEL, which makes sense in most cases, but not here. Wrap these
two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to
make sure we don't end up with the fs reclaim dependency under the
transaction dependency.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Since f8a53bb58ec7 ("btrfs: handle checksum generation in the storage
layer") the failures of btrfs_csum_one_bio() are handled via
bio_end_io().
This means, we can return BLK_STS_RESOURCE from btrfs_csum_one_bio() in
case the allocation of the ordered sums fails.
This also fixes a syzkaller report, where injecting a failure into the
kvzalloc() call results in a BUG_ON().
Reported-by: syzbot+d8941552e21eac774778@syzkaller.appspotmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently we allow a block group not to be marked read-only for scrub.
But for RAID56 block groups if we require the block group to be
read-only, then we're allowed to use cached content from scrub stripe to
reduce unnecessary RAID56 reads.
So this patch would:
- Make btrfs_inc_block_group_ro() try harder
During my tests, for cases like btrfs/061 and btrfs/064, we can hit
ENOSPC from btrfs_inc_block_group_ro() calls during scrub.
The reason is if we only have one single data chunk, and trying to
scrub it, we won't have any space left for any newer data writes.
But this check should be done by the caller, especially for scrub
cases we only temporarily mark the chunk read-only.
And newer data writes would always try to allocate a new data chunk
when needed.
- Return error for scrub if we failed to mark a RAID56 chunk read-only
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
make W=1 warns about a missing prototype that is defined but
not visible at point where simple_dname() is defined:
fs/d_path.c:317:7: error: no previous prototype for 'simple_dname' [-Werror=missing-prototypes]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Message-Id: <20230516195444.551461-1-arnd@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The motivation for this patch has been to enable using a stricter
apparmor profile to prevent programs from reading any coredump in the
system.
However, this became something else. The following details are based on
Christian's and Linus' archeology into the history of the number "2" in
the coredump handling code.
To make sure we're not accidently introducing some subtle behavioral
change into the coredump code we set out on a voyage into the depths of
history.git to figure out why this was O_RDWR in the first place.
Coredump handling was introduced over 30 years ago in commit
ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)").
The original code used O_WRONLY:
open_namei("core",O_CREAT | O_WRONLY | O_TRUNC,0600,&inode,NULL)
However, this changed in 1993 and starting with commit
9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") the coredump code
suddenly used the constant "2":
open_namei("core",O_CREAT | 2 | O_TRUNC,0600,&inode,NULL)
This was curious as in the same commit the kernel switched from
constants to proper defines in other places such as KERNEL_DS and
USER_DS and O_RDWR did already exist.
So why was "2" used? It turns out that open_namei() - an early version
of what later turned into filp_open() - didn't accept O_RDWR.
A semantic quirk of the open() uapi is the definition of the O_RDONLY
flag. It would seem natural to define:
#define O_RDWR (O_RDONLY | O_WRONLY)
but that isn't possible because:
#define O_RDONLY 0
This makes O_RDONLY effectively meaningless when passed to the kernel.
In other words, there has never been a way - until O_PATH at least - to
open a file without any permission; O_RDONLY was always implied on the
uapi side while the kernel does in fact allow opening files without
permissions.
The trouble comes when trying to map the uapi flags onto the
corresponding file mode flags FMODE_{READ,WRITE}. This mapping still
happens today and is causing issues to this day (We ran into this
during additions for openat2() for example.).
So the special value "3" was used to indicate that the file was opened
for special access:
f->f_flags = flag = flags;
f->f_mode = (flag+1) & O_ACCMODE;
if (f->f_mode)
flag++;
This allowed the file mode to be set to FMODE_READ | FMODE_WRITE mapping
the O_{RDONLY,WRONLY,RDWR} flags into the FMODE_{READ,WRITE} flags. The
special access then required read-write permissions and 0 was used to
access symlinks.
But back when ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") added
coredump handling open_namei() took the FMODE_{READ,WRITE} flags as an
argument. So the coredump handling introduced in
ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") was buggy because
O_WRONLY shouldn't have been passed. Since O_WRONLY is 1 but
open_namei() took FMODE_{READ,WRITE} it was passed FMODE_READ on
accident.
So 9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") was a bugfix
for this and the 2 didn't really mean O_RDWR, it meant FMODE_WRITE which
was correct.
The clue is that FMODE_{READ,WRITE} didn't exist yet and thus a raw "2"
value was passed.
Fast forward 5 years when around 2.2.4pre4 (February 16, 1999) this code
was changed to:
- dentry = open_namei(corefile,O_CREAT | 2 | O_TRUNC | O_NOFOLLOW, 0600);
...
+ file = filp_open(corefile,O_CREAT | 2 | O_TRUNC | O_NOFOLLOW, 0600);
At this point the raw "2" should have become O_WRONLY again as
filp_open() didn't take FMODE_{READ,WRITE} but O_{RDONLY,WRONLY,RDWR}.
Another 17 years later, the code was changed again cementing the mistake
and making it almost impossible to detect when commit
378c6520e7d2 ("fs/coredump: prevent fsuid=0 dumps into user-controlled directories")
replaced the raw "2" with O_RDWR.
And now, here we are with this patch that sent us on a quest to answer
the big questions in life such as "Why are coredump files opened with
O_RDWR?" and "Is it safe to just use O_WRONLY?".
So with this commit we're reintroducing O_WRONLY again and bringing this
code back to its original state when it was first introduced in commit
ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") over 30 years ago.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230420120409.602576-1-vsementsov@yandex-team.ru>
[brauner@kernel.org: completely rewritten commit message]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.
[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
|
|
clc length is now accepted to <= 8 less than length,
rather than < 8.
Solve issues on some of Axis's smb clients which send
messages where clc length is 8 bytes less than length.
The specific client was running kernel 4.19.217 with
smb dialect 3.0.2 on armv7l.
Cc: stable@vger.kernel.org
Signed-off-by: Gustav Johansson <gustajo@axis.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
ksmbd_smb2_check_message allows client to return one byte more, so we
need to allocate additional memory in ksmbd_conn_handler_loop to avoid
out-of-bound access.
Cc: stable@vger.kernel.org
Signed-off-by: Chih-Yen Chang <cc85nod@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
The offset of UserName is related to the address of security
buffer. To ensure the validaty of UserName, we need to compare name_off
+ name_len with secbuf_len instead of auth_msg_len.
[ 27.096243] ==================================================================
[ 27.096890] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x188/0x350
[ 27.097609] Read of size 2 at addr ffff888005e3b542 by task kworker/0:0/7
...
[ 27.099950] Call Trace:
[ 27.100194] <TASK>
[ 27.100397] dump_stack_lvl+0x33/0x50
[ 27.100752] print_report+0xcc/0x620
[ 27.102305] kasan_report+0xae/0xe0
[ 27.103072] kasan_check_range+0x35/0x1b0
[ 27.103757] smb_strndup_from_utf16+0x188/0x350
[ 27.105474] smb2_sess_setup+0xaf8/0x19c0
[ 27.107935] handle_ksmbd_work+0x274/0x810
[ 27.108315] process_one_work+0x419/0x760
[ 27.108689] worker_thread+0x2a2/0x6f0
[ 27.109385] kthread+0x160/0x190
[ 27.110129] ret_from_fork+0x1f/0x30
[ 27.110454] </TASK>
Cc: stable@vger.kernel.org
Signed-off-by: Chih-Yen Chang <cc85nod@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Add tag_len argument in smb2_find_context_vals() to avoid out-of-bound
read when create_context's name_len is larger than tag length.
[ 7.995411] ==================================================================
[ 7.995866] BUG: KASAN: global-out-of-bounds in memcmp+0x83/0xa0
[ 7.996248] Read of size 8 at addr ffffffff8258d940 by task kworker/0:0/7
...
[ 7.998191] Call Trace:
[ 7.998358] <TASK>
[ 7.998503] dump_stack_lvl+0x33/0x50
[ 7.998743] print_report+0xcc/0x620
[ 7.999458] kasan_report+0xae/0xe0
[ 7.999895] kasan_check_range+0x35/0x1b0
[ 8.000152] memcmp+0x83/0xa0
[ 8.000347] smb2_find_context_vals+0xf7/0x1e0
[ 8.000635] smb2_open+0x1df2/0x43a0
[ 8.006398] handle_ksmbd_work+0x274/0x810
[ 8.006666] process_one_work+0x419/0x760
[ 8.006922] worker_thread+0x2a2/0x6f0
[ 8.007429] kthread+0x160/0x190
[ 8.007946] ret_from_fork+0x1f/0x30
[ 8.008181] </TASK>
Cc: stable@vger.kernel.org
Signed-off-by: Chih-Yen Chang <cc85nod@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
This patch adds the trace point to ext2 direct-io apis
in fs/ext2/file.c
Here is how the output looks like
a.out-467865 [006] 6758.170968: ext2_dio_write_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT|WRITE aio 1 ret 0
a.out-467865 [006] 6758.171061: ext2_dio_write_end: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 0 flags DIRECT|WRITE aio 1 ret -529
kworker/3:153-444162 [003] 6758.171252: ext2_dio_write_endio: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT|WRITE aio 1 ret 0
a.out-468222 [001] 6761.628924: ext2_dio_read_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 1 ret 0
a.out-468222 [001] 6761.629063: ext2_dio_read_end: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 0 flags DIRECT aio 1 ret -529
a.out-468428 [005] 6763.937454: ext2_dio_write_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
a.out-468428 [005] 6763.937829: ext2_dio_write_endio: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
a.out-468428 [005] 6763.937847: ext2_dio_write_end: dev 7:12 ino 0xe isize 0x1000 pos 0x1000 len 0 flags DIRECT aio 0 ret 4096
a.out-468609 [000] 6765.702878: ext2_dio_read_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
a.out-468609 [000] 6765.703243: ext2_dio_read_end: dev 7:12 ino 0xe isize 0x1000 pos 0x1000 len 0 flags DIRECT aio 0 ret 4096
Reported-and-tested-by: Disha Goel <disgoel@linux.ibm.com>
[Need to add CFLAGS_trace for fixing unable to find trace file problem]
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <b8b0897fa2b273a448d7b4ba7317357ac73c08bc.1682069716.git.ritesh.list@gmail.com>
|
|
This patch converts ext2 direct-io path to iomap interface.
- This also takes care of DIO_SKIP_HOLES part in which we return -ENOTBLK
from ext2_iomap_begin(), in case if the write is done on a hole.
- This fallbacks to buffered-io in case of DIO_SKIP_HOLES or in case of
a partial write or if any error is detected in ext2_iomap_end().
We try to return -ENOTBLK in such cases.
- For any unaligned or extending DIO writes, we pass
IOMAP_DIO_FORCE_WAIT flag to ensure synchronous writes.
- For extending writes we set IOMAP_F_DIRTY in ext2_iomap_begin because
otherwise with dsync writes on devices that support FUA, generic_write_sync
won't be called and we might miss inode metadata updates.
- Since ext2 already now uses _nolock vartiant of sync write. Hence
there is no inode lock problem with iomap in this patch.
- ext2_iomap_ops are now being shared by DIO, DAX & fiemap path
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <610b672a52f2a7ff6dc550fd14d0f995806232a5.1682069716.git.ritesh.list@gmail.com>
|
|
Next patch converts ext2 to use iomap interface for DIO.
iomap layer can call generic_write_sync() -> ext2_fsync() from
iomap_dio_complete while still holding the inode_lock().
Now writeback from other paths doesn't need inode_lock().
It seems there is also no need of an inode_lock() for
sync_mapping_buffers(). It uses it's own mapping->private_lock
for it's buffer list handling.
Hence this patch is in preparation to move ext2 to iomap.
This uses generic_buffers_fsync() which does not take any inode_lock()
in ext2_fsync().
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <76d206a464574ff91db25bc9e43479b51ca7e307.1682069716.git.ritesh.list@gmail.com>
|
|
ext4 when got converted to iomap for dio, it copied __generic_file_fsync
implementation to avoid taking inode_lock in order to avoid any deadlock
(since iomap takes an inode_lock while calling generic_write_sync()).
The previous patch already added generic_buffers_fsync*() which does not
take any inode_lock(). Hence kill the redundant code and use
generic_buffers_fsync_noflush() function instead.
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <b43d4bb4403061ed86510c9587673e30a461ba14.1682069716.git.ritesh.list@gmail.com>
|
|
Some of the higher layers like iomap takes inode_lock() when calling
generic_write_sync().
Also writeback already happens from other paths without inode lock,
so it's difficult to say that we really need sync_mapping_buffers() to
take any inode locking here. Having said that, let's add
generic_buffers_fsync/_noflush() implementation in buffer.c with no
inode_lock/unlock() for now so that filesystems like ext2 and
ext4's nojournal mode can use it.
Ext4 when got converted to iomap for direct-io already copied it's own
variant of __generic_file_fsync() without lock.
This patch adds generic_buffers_fsync()
& generic_buffers_fsync_noflush() implementations for use in filesystems
like ext2 & ext4 respectively.
Later we can review other filesystems as well to see if we can make
generic_buffers_fsync/_noflush() which does not take any inode_lock() as
the default path.
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <d573408ac8408627d23a3d2d166e748c172c4c9e.1682069716.git.ritesh.list@gmail.com>
|
|
PAGE_ALIGN(x) macro gives the next highest value which is multiple of
pagesize. But if x is already page aligned then it simply returns x.
So, if x passed is 0 in dax_zero_range() function, that means the
length gets passed as 0 to ->iomap_begin().
In ext2 it then calls ext2_get_blocks -> max_blocks as 0 and hits bug_on
here in ext2_get_blocks().
BUG_ON(maxblocks == 0);
Instead we should be calling dax_truncate_page() here which takes
care of it. i.e. it only calls dax_zero_range if the offset is not
page/block aligned.
This can be easily triggered with following on fsdax mounted pmem
device.
dd if=/dev/zero of=file count=1 bs=512
truncate -s 0 file
[79.525838] EXT2-fs (pmem0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk
[79.529376] ext2 filesystem being mounted at /mnt1/test supports timestamps until 2038 (0x7fffffff)
[93.793207] ------------[ cut here ]------------
[93.795102] kernel BUG at fs/ext2/inode.c:637!
[93.796904] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[93.798659] CPU: 0 PID: 1192 Comm: truncate Not tainted 6.3.0-rc2-xfstests-00056-g131086faa369 #139
[93.806459] RIP: 0010:ext2_get_blocks.constprop.0+0x524/0x610
<...>
[93.835298] Call Trace:
[93.836253] <TASK>
[93.837103] ? lock_acquire+0xf8/0x110
[93.838479] ? d_lookup+0x69/0xd0
[93.839779] ext2_iomap_begin+0xa7/0x1c0
[93.841154] iomap_iter+0xc7/0x150
[93.842425] dax_zero_range+0x6e/0xa0
[93.843813] ext2_setsize+0x176/0x1b0
[93.845164] ext2_setattr+0x151/0x200
[93.846467] notify_change+0x341/0x4e0
[93.847805] ? lock_acquire+0xf8/0x110
[93.849143] ? do_truncate+0x74/0xe0
[93.850452] ? do_truncate+0x84/0xe0
[93.851739] do_truncate+0x84/0xe0
[93.852974] do_sys_ftruncate+0x2b4/0x2f0
[93.854404] do_syscall_64+0x3f/0x90
[93.855789] entry_SYSCALL_64_after_hwframe+0x72/0xdc
CC: stable@vger.kernel.org
Fixes: 2aa3048e03d3 ("iomap: switch iomap_zero_range to use iomap_iter")
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <046a58317f29d9603d1068b2bbae47c2332c17ae.1682069716.git.ritesh.list@gmail.com>
|
|
Instead of open coding a __dynamic_array(), use the __string() and
__assign_str() helper macros that exist for this kind of use case.
Part of an effort to remove deprecated strlcpy() [1] completely from the
kernel[2].
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Fixes: 3c92fba557c6 ("NFSD: Enhance the nfsd_cb_setup tracepoint")
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
|
|
Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY to fixes
the following sparce warnings:
fs/overlayfs/file.c:48:37: sparse: warning: restricted fmode_t degrades to integer
fs/overlayfs/file.c:128:13: sparse: warning: restricted fmode_t degrades to integer
fs/open.c:1159:21: sparse: warning: restricted fmode_t degrades to integer
Signed-off-by: Min-Hua Chen <minhuadotchen@gmail.com>
Message-Id: <20230502232210.119063-1-minhuadotchen@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Use kcalloc() for allocation/flush of 128 pointers table to
reduce stack usage.
Function now returns -ENOMEM or 0 on success.
stackusage
Before:
./fs/jffs2/xattr.c:775 jffs2_build_xattr_subsystem 1208
dynamic,bounded
After:
./fs/jffs2/xattr.c:775 jffs2_build_xattr_subsystem 192
dynamic,bounded
Also update definition when CONFIG_JFFS2_FS_XATTR is not enabled
Tested with an MTD mount point and some user set/getfattr.
Many current target on OpenWRT also suffer from a compilation warning
(that become an error with CONFIG_WERROR) with the following output:
fs/jffs2/xattr.c: In function 'jffs2_build_xattr_subsystem':
fs/jffs2/xattr.c:887:1: error: the frame size of 1088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
887 | }
| ^
Using dynamic allocation fix this compilation warning.
Fixes: c9f700f840bd ("[JFFS2][XATTR] using 'delete marker' for xdatum/xref deletion")
Reported-by: Tim Gardner <tim.gardner@canonical.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Ron Economos <re@w6rz.net>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Cc: stable@vger.kernel.org
Message-Id: <20230506045612.16616-1-ansuelsmth@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
fs/open.c: In functions 'setattr_vfsuid' and 'setattr_vfsgid':
warning: Function parameter or member 'attr' not described
- Fix warning by removing kernel-doc for these as they are static
inline functions and not required to be exposed via kernel-doc.
fs/open.c:
warning: Excess function parameter 'opened' description in 'finish_open'
warning: Excess function parameter 'cred' description in 'vfs_open'
- Fix by removing the parameters from the kernel-doc as they are no
longer required by the function.
Signed-off-by: Anuradha Weeraman <anuradha@debian.org>
Message-Id: <20230506182928.384105-1-anuradha@debian.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Message-Id: <20230510221119.3508930-1-azeemshaikh38@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Fix the following sparse warnings by using __poll_t instead
of unsigned type.
fs/eventpoll.c:541:9: sparse: warning: restricted __poll_t degrades to integer
fs/eventfd.c:67:17: sparse: warning: restricted __poll_t degrades to integer
Signed-off-by: Min-Hua Chen <minhuadotchen@gmail.com>
Message-Id: <20230511164628.336586-1-minhuadotchen@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Some ext4 bug fixes (mostly to address Syzbot reports)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: bail out of ext4_xattr_ibody_get() fails for any reason
ext4: add bounds checking in get_max_inline_xattr_value_size()
ext4: add indication of ro vs r/w mounts in the mount message
ext4: fix deadlock when converting an inline directory in nojournal mode
ext4: improve error recovery code paths in __ext4_remount()
ext4: improve error handling from ext4_dirhash()
ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled
ext4: check iomap type only if ext4_iomap_begin() does not fail
ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum
ext4: fix data races when using cached status extents
ext4: avoid deadlock in fs reclaim with page writeback
ext4: fix invalid free tracking in ext4_xattr_move_to_block()
ext4: remove a BUG_ON in ext4_mb_release_group_pa()
ext4: allow ext4_get_group_info() to fail
ext4: fix lockdep warning when enabling MMP
ext4: fix WARNING in mb_find_extent
|
|
In ext4_update_inline_data(), if ext4_xattr_ibody_get() fails for any
reason, it's best if we just fail as opposed to stumbling on,
especially if the failure is EFSCORRUPTED.
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted. Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.
Reported-by: syzbot+1966db24521e5f6e23f7@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=1966db24521e5f6e23f7
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Whether the file system is mounted read-only or read/write is more
important than the quota mode, which we are already printing. Add the
ro vs r/w indication since this can be helpful in debugging problems
from the console log.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
In no journal mode, ext4_finish_convert_inline_dir() can self-deadlock
by calling ext4_handle_dirty_dirblock() when it already has taken the
directory lock. There is a similar self-deadlock in
ext4_incvert_inline_data_nolock() for data files which we'll fix at
the same time.
A simple reproducer demonstrating the problem:
mke2fs -Fq -t ext2 -O inline_data -b 4k /dev/vdc 64
mount -t ext4 -o dirsync /dev/vdc /vdc
cd /vdc
mkdir file0
cd file0
touch file0
touch file1
attr -s BurnSpaceInEA -V abcde .
touch supercalifragilisticexpialidocious
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230507021608.1290720-1-tytso@mit.edu
Reported-by: syzbot+91dccab7c64e2850a4e5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ba84cc80a9491d65416bc7877e1650c87530fe8a
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
If there are failures while changing the mount options in
__ext4_remount(), we need to restore the old mount options.
This commit fixes two problem. The first is there is a chance that we
will free the old quota file names before a potential failure leading
to a use-after-free. The second problem addressed in this commit is
if there is a failed read/write to read-only transition, if the quota
has already been suspended, we need to renable quota handling.
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
The ext4_dirhash() will *almost* never fail, especially when the hash
tree feature was first introduced. However, with the addition of
support of encrypted, casefolded file names, that function can most
certainly fail today.
So make sure the callers of ext4_dirhash() properly check for
failures, and reflect the errors back up to their callers.
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-1-tytso@mit.edu
Reported-by: syzbot+394aa8a792cb99dbc837@syzkaller.appspotmail.com
Reported-by: syzbot+344aaa8697ebd232bfc8@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=db56459ea4ac4a676ae4b4678f633e55da005a9b
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When a file system currently mounted read/only is remounted
read/write, if we clear the SB_RDONLY flag too early, before the quota
is initialized, and there is another process/thread constantly
attempting to create a directory, it's possible to trigger the
WARN_ON_ONCE(dquot_initialize_needed(inode));
in ext4_xattr_block_set(), with the following stack trace:
WARNING: CPU: 0 PID: 5338 at fs/ext4/xattr.c:2141 ext4_xattr_block_set+0x2ef2/0x3680
RIP: 0010:ext4_xattr_block_set+0x2ef2/0x3680 fs/ext4/xattr.c:2141
Call Trace:
ext4_xattr_set_handle+0xcd4/0x15c0 fs/ext4/xattr.c:2458
ext4_initxattrs+0xa3/0x110 fs/ext4/xattr_security.c:44
security_inode_init_security+0x2df/0x3f0 security/security.c:1147
__ext4_new_inode+0x347e/0x43d0 fs/ext4/ialloc.c:1324
ext4_mkdir+0x425/0xce0 fs/ext4/namei.c:2992
vfs_mkdir+0x29d/0x450 fs/namei.c:4038
do_mkdirat+0x264/0x520 fs/namei.c:4061
__do_sys_mkdirat fs/namei.c:4076 [inline]
__se_sys_mkdirat fs/namei.c:4074 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4074
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-1-tytso@mit.edu
Reported-by: syzbot+6385d7d3065524c5ca6d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=6513f6cb5cd6b5fc9f37e3bb70d273b94be9c34c
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may
fail for some reason (e.g. memory allocation failure, bare disk write), and
later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4
iomap_begin() returns an error, it is normal that the type of iomap->type
may not match the expectation. Therefore, we only determine if iomap->type
is as expected when ext4_iomap_begin() is executed successfully.
Cc: stable@kernel.org
Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@google.com
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When modifying the block device while it is mounted by the filesystem,
syzbot reported the following:
BUG: KASAN: slab-out-of-bounds in crc16+0x206/0x280 lib/crc16.c:58
Read of size 1 at addr ffff888075f5c0a8 by task syz-executor.2/15586
CPU: 1 PID: 15586 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00205-gc96618275234 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:306
print_report+0x107/0x1f0 mm/kasan/report.c:417
kasan_report+0xcd/0x100 mm/kasan/report.c:517
crc16+0x206/0x280 lib/crc16.c:58
ext4_group_desc_csum+0x81b/0xb20 fs/ext4/super.c:3187
ext4_group_desc_csum_set+0x195/0x230 fs/ext4/super.c:3210
ext4_mb_clear_bb fs/ext4/mballoc.c:6027 [inline]
ext4_free_blocks+0x191a/0x2810 fs/ext4/mballoc.c:6173
ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
ext4_ext_remove_space+0x24ef/0x46a0 fs/ext4/extents.c:2958
ext4_ext_truncate+0x177/0x220 fs/ext4/extents.c:4416
ext4_truncate+0xa6a/0xea0 fs/ext4/inode.c:4342
ext4_setattr+0x10c8/0x1930 fs/ext4/inode.c:5622
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
handle_truncate fs/namei.c:3216 [inline]
do_open fs/namei.c:3561 [inline]
path_openat+0x272b/0x2dd0 fs/namei.c:3714
do_filp_open+0x264/0x4f0 fs/namei.c:3741
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_creat fs/open.c:1402 [inline]
__se_sys_creat fs/open.c:1396 [inline]
__x64_sys_creat+0x11f/0x160 fs/open.c:1396
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f72f8a8c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f72f97e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f72f8bac050 RCX: 00007f72f8a8c0c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f72f8ae7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd165348bf R14: 00007f72f97e3300 R15: 0000000000022000
Replace
le16_to_cpu(sbi->s_es->s_desc_size)
with
sbi->s_desc_size
It reduces ext4's compiled text size, and makes the code more efficient
(we remove an extra indirect reference and a potential byte
swap on big endian systems), and there is no downside. It also avoids the
potential KASAN / syzkaller failure, as a bonus.
Reported-by: syzbot+fc51227e7100c9294894@syzkaller.appspotmail.com
Reported-by: syzbot+8785e41224a3afd04321@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=70d28d11ab14bd7938f3e088365252aa923cff42
Link: https://syzkaller.appspot.com/bug?id=b85721b38583ecc6b5e72ff524c67302abbc30f3
Link: https://lore.kernel.org/all/000000000000ece18705f3b20934@google.com/
Fixes: 717d50e4971b ("Ext4: Uninitialized Block Groups")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230504121525.3275886-1-tudor.ambarus@linaro.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When using cached extent stored in extent status tree in tree->cache_es
another process holding ei->i_es_lock for reading can be racing with us
setting new value of tree->cache_es. If the compiler would decide to
refetch tree->cache_es at an unfortunate moment, it could result in a
bogus in_range() check. Fix the possible race by using READ_ONCE() when
using tree->cache_es only under ei->i_es_lock for reading.
Cc: stable@kernel.org
Reported-by: syzbot+4a03518df1e31b537066@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000d3b33905fa0fd4a6@google.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230504125524.10802-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
