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2018-11-19block: avoid ordered task state change for polled IOJens Axboe
For the core poll helper, the task state setting don't need to imply any atomics, as it's the current task itself that is being modified and we're not going to sleep. For IRQ driven, the wakeup path have the necessary barriers to not need us using the heavy handed version of the task state setting. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-18Merge tag 'v4.20-rc3' into for-4.21/blockJens Axboe
Merge in -rc3 to resolve a few conflicts, but also to get a few important fixes that have gone into mainline since the block 4.21 branch was forked off (most notably the SCSI queue issue, which is both a conflict AND needed fix). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-18ocfs2: free up write context when direct IO failedWengang Wang
The write context should also be freed even when direct IO failed. Otherwise a memory leak is introduced and entries remain in oi->ip_unwritten_list causing the following BUG later in unlink path: ERROR: bug expression: !list_empty(&oi->ip_unwritten_list) ERROR: Clear inode of 215043, inode has unwritten extents ... Call Trace: ? __set_current_blocked+0x42/0x68 ocfs2_evict_inode+0x91/0x6a0 [ocfs2] ? bit_waitqueue+0x40/0x33 evict+0xdb/0x1af iput+0x1a2/0x1f7 do_unlinkat+0x194/0x28f SyS_unlinkat+0x1b/0x2f do_syscall_64+0x79/0x1ae entry_SYSCALL_64_after_hwframe+0x151/0x0 This patch also logs, with frequency limit, direct IO failures. Link: http://lkml.kernel.org/r/20181102170632.25921-1-wen.gang.wang@oracle.com Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Changwei Ge <ge.changwei@h3c.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18mm: don't reclaim inodes with many attached pagesRoman Gushchin
Spock reported that commit 172b06c32b94 ("mm: slowly shrink slabs with a relatively small number of objects") leads to a regression on his setup: periodically the majority of the pagecache is evicted without an obvious reason, while before the change the amount of free memory was balancing around the watermark. The reason behind is that the mentioned above change created some minimal background pressure on the inode cache. The problem is that if an inode is considered to be reclaimed, all belonging pagecache page are stripped, no matter how many of them are there. So, if a huge multi-gigabyte file is cached in the memory, and the goal is to reclaim only few slab objects (unused inodes), we still can eventually evict all gigabytes of the pagecache at once. The workload described by Spock has few large non-mapped files in the pagecache, so it's especially noticeable. To solve the problem let's postpone the reclaim of inodes, which have more than 1 attached page. Let's wait until the pagecache pages will be evicted naturally by scanning the corresponding LRU lists, and only then reclaim the inode structure. Link: http://lkml.kernel.org/r/20181023164302.20436-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reported-by: Spock <dairinin@gmail.com> Tested-by: Spock <dairinin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: <stable@vger.kernel.org> [4.19.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-16Merge tag 'fsnotify_for_v4.20-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify fix from Jan Kara: "One small fsnotify fix for duplicate events" * tag 'fsnotify_for_v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fanotify: fix handling of events on child sub-directory
2018-11-16Merge tag 'gfs2-4.20.fixes3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull bfs2 fixes from Andreas Gruenbacher: "Fix two bugs leading to leaked buffer head references: - gfs2: Put bitmap buffers in put_super - gfs2: Fix iomap buffer head reference counting bug And one bug leading to significant slow-downs when deleting large files: - gfs2: Fix metadata read-ahead during truncate (2)" * tag 'gfs2-4.20.fixes3' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix iomap buffer head reference counting bug gfs2: Fix metadata read-ahead during truncate (2) gfs2: Put bitmap buffers in put_super
2018-11-16gfs2: Fix iomap buffer head reference counting bugAndreas Gruenbacher
GFS2 passes the inode buffer head (dibh) from gfs2_iomap_begin to gfs2_iomap_end in iomap->private. It sets that private pointer in gfs2_iomap_get. Users of gfs2_iomap_get other than gfs2_iomap_begin would have to release iomap->private, but this isn't done correctly, leading to a leak of buffer head references. To fix this, move the code for setting iomap->private from gfs2_iomap_get to gfs2_iomap_begin. Fixes: 64bc06bb32 ("gfs2: iomap buffered write support") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-16block: don't plug for aio/O_DIRECT HIPRI IOJens Axboe
Those will go straight to issue inside blk-mq, so don't bother setting up a block plug for them. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-16block: for async O_DIRECT, mark us as polling if asked toJens Axboe
Inherit the iocb IOCB_HIPRI flag, and pass on REQ_HIPRI for those kinds of requests. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-16block: add polled wakeup task helperJens Axboe
If we're polling for IO on a device that doesn't use interrupts, then IO completion loop (and wake of task) is done by submitting task itself. If that is the case, then we don't need to enter the wake_up_process() function, we can simply mark ourselves as TASK_RUNNING. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-16Merge tag 'fuse-fixes-4.20-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse fixes from Miklos Szeredi: "A couple of fixes, all bound for -stable (i.e. not regressions in this cycle)" * tag 'fuse-fixes-4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: fix use-after-free in fuse_direct_IO() fuse: fix possibly missed wake-up after abort fuse: fix leaked notify reply
2018-11-15Merge tag 'nfs-for-4.20-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Stable fixes: - Don't exit the NFSv4 state manager without clearing NFS4CLNT_MANAGER_RUNNING Bugfixes: - Fix an Oops when destroying the RPCSEC_GSS credential cache - Fix an Oops during delegation callbacks - Ensure that the NFSv4 state manager exits the loop on SIGKILL - Fix a bogus get/put in generic_key_to_expire()" * tag 'nfs-for-4.20-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFSv4: Fix an Oops during delegation callbacks SUNRPC: Fix a bogus get/put in generic_key_to_expire() SUNRPC: Fix a Oops when destroying the RPCSEC_GSS credential cache NFSv4: Ensure that the state manager exits the loop on SIGKILL NFSv4: Don't exit the state manager without clearing NFS4CLNT_MANAGER_RUNNING
2018-11-14Merge tag 'nfsd-4.20-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd fixes from Bruce Fields: "Three nfsd bugfixes. None are new bugs, but they all take a little effort to hit, which might explain why they weren't found sooner" * tag 'nfsd-4.20-1' of git://linux-nfs.org/~bfields/linux: SUNRPC: drop pointless static qualifier in xdr_get_next_encode_buffer() nfsd: COPY and CLONE operations require the saved filehandle to be set sunrpc: correct the computation for page_ptr when truncating
2018-11-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace fix from Eric Biederman: "Benjamin Coddington noticed an unkillable busy loop in the kernel that anyone who is sufficiently motivated can trigger. This bug did not exist in earlier kernels making this bug a regression. I have tested the change personally and confirmed that the bug exists and that the fix works. This fix has been picked up by linux-next and hopefully the automated testing bots and no problems have been reported from those sources. Ordinarily I would let something like this sit a little longer but I am going to be away at Linux Plumbers the rest of this week and I am afraid if I don't send the pull request now this fix will get lost" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: mnt: fix __detach_mounts infinite loop
2018-11-13NFSv4: Fix an Oops during delegation callbacksTrond Myklebust
If the server sends a CB_GETATTR or a CB_RECALL while the filesystem is being unmounted, then we can Oops when releasing the inode in nfs4_callback_getattr() and nfs4_callback_recall(). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-11-12NFSv4: Ensure that the state manager exits the loop on SIGKILLTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-11-12NFSv4: Don't exit the state manager without clearing NFS4CLNT_MANAGER_RUNNINGTrond Myklebust
If we exit the NFSv4 state manager due to a umount, then we can end up leaving the NFS4CLNT_MANAGER_RUNNING flag set. If another mount causes the nfs4_client to be rereferenced before it is destroyed, then we end up never being able to recover state. Fixes: 47c2199b6eb5 ("NFSv4.1: Ensure state manager thread dies on last ...") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: stable@vger.kernel.org # v4.15+
2018-11-12mnt: fix __detach_mounts infinite loopBenjamin Coddington
Since commit ff17fa561a04 ("d_invalidate(): unhash immediately") immediately unhashes the dentry, we'll never return the mountpoint in lookup_mountpoint(), which can lead to an unbreakable loop in d_invalidate(). I have reports of NFS clients getting into this condition after the server removes an export of an existing mount created through follow_automount(), but I suspect there are various other ways to produce this problem if we hunt down users of d_invalidate(). For example, it is possible to get into this state by using XFS' d_invalidate() call in xfs_vn_unlink(): truncate -s 100m img{1,2} mkfs.xfs -q -n version=ci img1 mkfs.xfs -q -n version=ci img2 mkdir -p /mnt/xfs mount img1 /mnt/xfs mkdir /mnt/xfs/sub1 mount img2 /mnt/xfs/sub1 cat > /mnt/xfs/sub1/foo & umount -l /mnt/xfs/sub1 mount img2 /mnt/xfs/sub1 mount --make-private /mnt/xfs mkdir /mnt/xfs/sub2 mount --move /mnt/xfs/sub1 /mnt/xfs/sub2 rmdir /mnt/xfs/sub1 Fix this by moving the check for an unlinked dentry out of the detach_mounts() path. Fixes: ff17fa561a04 ("d_invalidate(): unhash immediately") Cc: stable@vger.kernel.org Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2018-11-11Merge tag 'for-4.20-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Several fixes to recent release (4.19, fixes tagged for stable) and other fixes" * tag 'for-4.20-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix missing delayed iputs on unmount Btrfs: fix data corruption due to cloning of eof block Btrfs: fix infinite loop on inode eviction after deduplication of eof block Btrfs: fix deadlock on tree root leaf when finding free extent btrfs: avoid link error with CONFIG_NO_AUTO_INLINE btrfs: tree-checker: Fix misleading group system information Btrfs: fix missing data checksums after a ranged fsync (msync) btrfs: fix pinned underflow after transaction aborted Btrfs: fix cur_offset in the error case for nocow
2018-11-11Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "A large number of ext4 bug fixes, mostly buffer and memory leaks on error return cleanup paths" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: missing !bh check in ext4_xattr_inode_write() ext4: fix buffer leak in __ext4_read_dirblock() on error path ext4: fix buffer leak in ext4_expand_extra_isize_ea() on error path ext4: fix buffer leak in ext4_xattr_move_to_block() on error path ext4: release bs.bh before re-using in ext4_xattr_block_find() ext4: fix buffer leak in ext4_xattr_get_block() on error path ext4: fix possible leak of s_journal_flag_rwsem in error path ext4: fix possible leak of sbi->s_group_desc_leak in error path ext4: remove unneeded brelse call in ext4_xattr_inode_update_ref() ext4: avoid possible double brelse() in add_new_gdb() on error path ext4: avoid buffer leak in ext4_orphan_add() after prior errors ext4: avoid buffer leak on shutdown in ext4_mark_iloc_dirty() ext4: fix possible inode leak in the retry loop of ext4_resize_fs() ext4: fix missing cleanup if ext4_alloc_flex_bg_array() fails while resizing ext4: add missing brelse() update_backups()'s error path ext4: add missing brelse() add_new_gdb_meta_bg()'s error path ext4: add missing brelse() in set_flexbg_block_bitmap()'s error path ext4: avoid potential extra brelse in setup_new_flex_group_blocks()
2018-11-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace fixes from Eric Biederman: "I believe all of these are simple obviously correct bug fixes. These fall into two groups: - Fixing the implementation of MNT_LOCKED which prevents lesser privileged users from seeing unders mounts created by more privileged users. - Fixing the extended uid and group mapping in user namespaces. As well as ensuring the code looks correct I have spot tested these changes as well and in my testing the fixes are working" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: mount: Prevent MNT_DETACH from disconnecting locked mounts mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts mount: Retest MNT_LOCKED in do_umount userns: also map extents in the reverse map to kernel IDs
2018-11-09Merge tag 'ceph-for-4.20-rc2' of https://github.com/ceph/ceph-clientLinus Torvalds
Pull Ceph fixes from Ilya Dryomov: "Two CephFS fixes (copy_file_range and quota) and a small feature bit cleanup" * tag 'ceph-for-4.20-rc2' of https://github.com/ceph/ceph-client: libceph: assume argonaut on the server side ceph: quota: fix null pointer dereference in quota check ceph: add destination file data sync before doing any remote copy
2018-11-09ext4: missing !bh check in ext4_xattr_inode_write()Vasily Averin
According to Ted Ts'o ext4_getblk() called in ext4_xattr_inode_write() should not return bh = NULL The only time that bh could be NULL, then, would be in the case of something really going wrong; a programming error elsewhere (perhaps a wild pointer dereference) or I/O error causing on-disk file system corruption (although that would be highly unlikely given that we had *just* allocated the blocks and so the metadata blocks in question probably would still be in the cache). Fixes: e50e5129f384 ("ext4: xattr-in-inode support") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.13
2018-11-09fuse: fix use-after-free in fuse_direct_IO()Lukas Czerner
In async IO blocking case the additional reference to the io is taken for it to survive fuse_aio_complete(). In non blocking case this additional reference is not needed, however we still reference io to figure out whether to wait for completion or not. This is wrong and will lead to use-after-free. Fix it by storing blocking information in separate variable. This was spotted by KASAN when running generic/208 fstest. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reported-by: Zorro Lang <zlang@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 744742d692e3 ("fuse: Add reference counting for fuse_io_priv") Cc: <stable@vger.kernel.org> # v4.6
2018-11-09fuse: fix possibly missed wake-up after abortMiklos Szeredi
In current fuse_drop_waiting() implementation it's possible that fuse_wait_aborted() will not be woken up in the unlikely case that fuse_abort_conn() + fuse_wait_aborted() runs in between checking fc->connected and calling atomic_dec(&fc->num_waiting). Do the atomic_dec_and_test() unconditionally, which also provides the necessary barrier against reordering with the fc->connected check. The explicit smp_mb() in fuse_wait_aborted() is not actually needed, since the spin_unlock() in fuse_abort_conn() provides the necessary RELEASE barrier after resetting fc->connected. However, this is not a performance sensitive path, and adding the explicit barrier makes it easier to document. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: b8f95e5d13f5 ("fuse: umount should wait for all requests") Cc: <stable@vger.kernel.org> #v4.19
2018-11-09fuse: fix leaked notify replyMiklos Szeredi
fuse_request_send_notify_reply() may fail if the connection was reset for some reason (e.g. fs was unmounted). Don't leak request reference in this case. Besides leaking memory, this resulted in fc->num_waiting not being decremented and hence fuse_wait_aborted() left in a hanging and unkillable state. Fixes: 2d45ba381a74 ("fuse: add retrieve request") Fixes: b8f95e5d13f5 ("fuse: umount should wait for all requests") Reported-and-tested-by: syzbot+6339eda9cb4ebbc4c37b@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> #v2.6.36
2018-11-09gfs2: Fix metadata read-ahead during truncate (2)Andreas Gruenbacher
The previous attempt to fix for metadata read-ahead during truncate was incorrect: for files with a height > 2 (1006989312 bytes with a block size of 4096 bytes), read-ahead requests were not being issued for some of the indirect blocks discovered while walking the metadata tree, leading to significant slow-downs when deleting large files. Fix that. In addition, only issue read-ahead requests in the first pass through the meta-data tree, while deallocating data blocks. Fixes: c3ce5aa9b0 ("gfs2: Fix metadata read-ahead during truncate") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-11-09gfs2: Put bitmap buffers in put_superAndreas Gruenbacher
gfs2_put_super calls gfs2_clear_rgrpd to destroy the gfs2_rgrpd objects attached to the resource group glocks. That function should release the buffers attached to the gfs2_bitmap objects (bi_bh), but the call to gfs2_rgrp_brelse for doing that is missing. When gfs2_releasepage later runs across these buffers which are still referenced, it refuses to free them. This causes the pages the buffers are attached to to remain referenced as well. With enough mount/unmount cycles, the system will eventually run out of memory. Fix this by adding the missing call to gfs2_rgrp_brelse in gfs2_clear_rgrpd. (Also fix a gfs2_rgrp_relse -> gfs2_rgrp_brelse typo in a comment.) Fixes: 39b0f1e92908 ("GFS2: Don't brelse rgrp buffer_heads every allocation") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-11-08nfsd: COPY and CLONE operations require the saved filehandle to be setScott Mayhew
Make sure we have a saved filehandle, otherwise we'll oops with a null pointer dereference in nfs4_preprocess_stateid_op(). Signed-off-by: Scott Mayhew <smayhew@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-11-08libceph: assume argonaut on the server sideIlya Dryomov
No one is running pre-argonaut. In addition one of the argonaut features (NOSRCADDR) has been required since day one (and a half, 2.6.34 vs 2.6.35) of the kernel client. Allow for the possibility of reusing these feature bits later. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Sage Weil <sage@redhat.com>
2018-11-08ceph: quota: fix null pointer dereference in quota checkLuis Henriques
This patch fixes a possible null pointer dereference in check_quota_exceeded, detected by the static checker smatch, with the following warning:    fs/ceph/quota.c:240 check_quota_exceeded()     error: we previously assumed 'realm' could be null (see line 188) Fixes: b7a2921765cf ("ceph: quota: support for ceph.quota.max_files") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Luis Henriques <lhenriques@suse.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-11-08ceph: add destination file data sync before doing any remote copyLuis Henriques
If we try to copy into a file that was just written, any data that is remote copied will be overwritten by our buffered writes once they are flushed.  When this happens, the call to invalidate_inode_pages2_range will also return a -EBUSY error. This patch fixes this by also sync'ing the destination file before starting any copy. Fixes: 503f82a9932d ("ceph: support copy_file_range file operation") Signed-off-by: Luis Henriques <lhenriques@suse.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-11-08fanotify: fix handling of events on child sub-directoryAmir Goldstein
When an event is reported on a sub-directory and the parent inode has a mark mask with FS_EVENT_ON_CHILD|FS_ISDIR, the event will be sent to fsnotify() even if the event type is not in the parent mark mask (e.g. FS_OPEN). Further more, if that event happened on a mount or a filesystem with a mount/sb mark that does have that event type in their mask, the "on child" event will be reported on the mount/sb mark. That is not desired, because user will get a duplicate event for the same action. Note that the event reported on the victim inode is never merged with the event reported on the parent inode, because of the check in should_merge(): old_fsn->inode == new_fsn->inode. Fix this by looking for a match of an actual event type (i.e. not just FS_ISDIR) in parent's inode mark mask and by not reporting an "on child" event to group if event type is only found on mount/sb marks. [backport hint: The bug seems to have always been in fanotify, but this patch will only apply cleanly to v4.19.y] Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-08mount: Prevent MNT_DETACH from disconnecting locked mountsEric W. Biederman
Timothy Baldwin <timbaldwin@fastmail.co.uk> wrote: > As per mount_namespaces(7) unprivileged users should not be able to look under mount points: > > Mounts that come as a single unit from more privileged mount are locked > together and may not be separated in a less privileged mount namespace. > > However they can: > > 1. Create a mount namespace. > 2. In the mount namespace open a file descriptor to the parent of a mount point. > 3. Destroy the mount namespace. > 4. Use the file descriptor to look under the mount point. > > I have reproduced this with Linux 4.16.18 and Linux 4.18-rc8. > > The setup: > > $ sudo sysctl kernel.unprivileged_userns_clone=1 > kernel.unprivileged_userns_clone = 1 > $ mkdir -p A/B/Secret > $ sudo mount -t tmpfs hide A/B > > > "Secret" is indeed hidden as expected: > > $ ls -lR A > A: > total 0 > drwxrwxrwt 2 root root 40 Feb 12 21:08 B > > A/B: > total 0 > > > The attack revealing "Secret": > > $ unshare -Umr sh -c "exec unshare -m ls -lR /proc/self/fd/4/ 4<A" > /proc/self/fd/4/: > total 0 > drwxr-xr-x 3 root root 60 Feb 12 21:08 B > > /proc/self/fd/4/B: > total 0 > drwxr-xr-x 2 root root 40 Feb 12 21:08 Secret > > /proc/self/fd/4/B/Secret: > total 0 I tracked this down to put_mnt_ns running passing UMOUNT_SYNC and disconnecting all of the mounts in a mount namespace. Fix this by factoring drop_mounts out of drop_collected_mounts and passing 0 instead of UMOUNT_SYNC. There are two possible behavior differences that result from this. - No longer setting UMOUNT_SYNC will no longer set MNT_SYNC_UMOUNT on the vfsmounts being unmounted. This effects the lazy rcu walk by kicking the walk out of rcu mode and forcing it to be a non-lazy walk. - No longer disconnecting locked mounts will keep some mounts around longer as they stay because the are locked to other mounts. There are only two users of drop_collected mounts: audit_tree.c and put_mnt_ns. In audit_tree.c the mounts are private and there are no rcu lazy walks only calls to iterate_mounts. So the changes should have no effect except for a small timing effect as the connected mounts are disconnected. In put_mnt_ns there may be references from process outside the mount namespace to the mounts. So the mounts remaining connected will be the bug fix that is needed. That rcu walks are allowed to continue appears not to be a problem especially as the rcu walk change was about an implementation detail not about semantics. Cc: stable@vger.kernel.org Fixes: 5ff9d8a65ce8 ("vfs: Lock in place mounts from more privileged users") Reported-by: Timothy Baldwin <timbaldwin@fastmail.co.uk> Tested-by: Timothy Baldwin <timbaldwin@fastmail.co.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-11-08mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mountsEric W. Biederman
Jonathan Calmels from NVIDIA reported that he's able to bypass the mount visibility security check in place in the Linux kernel by using a combination of the unbindable property along with the private mount propagation option to allow a unprivileged user to see a path which was purposefully hidden by the root user. Reproducer: # Hide a path to all users using a tmpfs root@castiana:~# mount -t tmpfs tmpfs /sys/devices/ root@castiana:~# # As an unprivileged user, unshare user namespace and mount namespace stgraber@castiana:~$ unshare -U -m -r # Confirm the path is still not accessible root@castiana:~# ls /sys/devices/ # Make /sys recursively unbindable and private root@castiana:~# mount --make-runbindable /sys root@castiana:~# mount --make-private /sys # Recursively bind-mount the rest of /sys over to /mnnt root@castiana:~# mount --rbind /sys/ /mnt # Access our hidden /sys/device as an unprivileged user root@castiana:~# ls /mnt/devices/ breakpoint cpu cstate_core cstate_pkg i915 intel_pt isa kprobe LNXSYSTM:00 msr pci0000:00 platform pnp0 power software system tracepoint uncore_arb uncore_cbox_0 uncore_cbox_1 uprobe virtual Solve this by teaching copy_tree to fail if a mount turns out to be both unbindable and locked. Cc: stable@vger.kernel.org Fixes: 5ff9d8a65ce8 ("vfs: Lock in place mounts from more privileged users") Reported-by: Jonathan Calmels <jcalmels@nvidia.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-11-08mount: Retest MNT_LOCKED in do_umountEric W. Biederman
It was recently pointed out that the one instance of testing MNT_LOCKED outside of the namespace_sem is in ksys_umount. Fix that by adding a test inside of do_umount with namespace_sem and the mount_lock held. As it helps to fail fails the existing test is maintained with an additional comment pointing out that it may be racy because the locks are not held. Cc: stable@vger.kernel.org Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Fixes: 5ff9d8a65ce8 ("vfs: Lock in place mounts from more privileged users") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-11-07ext4: fix buffer leak in __ext4_read_dirblock() on error pathVasily Averin
Fixes: dc6982ff4db1 ("ext4: refactor code to read directory blocks ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.9
2018-11-07block: add REQ_HIPRI and inherit it from IOCB_HIPRIJens Axboe
We use IOCB_HIPRI to poll for IO in the caller instead of scheduling. This information is not available for (or after) IO submission. The driver may make different queue choices based on the type of IO, so make the fact that we will poll for this IO known to the lower layers as well. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07Btrfs: fix missing delayed iputs on unmountOmar Sandoval
There's a race between close_ctree() and cleaner_kthread(). close_ctree() sets btrfs_fs_closing(), and the cleaner stops when it sees it set, but this is racy; the cleaner might have already checked the bit and could be cleaning stuff. In particular, if it deletes unused block groups, it will create delayed iputs for the free space cache inodes. As of "btrfs: don't run delayed_iputs in commit", we're no longer running delayed iputs after a commit. Therefore, if the cleaner creates more delayed iputs after delayed iputs are run in btrfs_commit_super(), we will leak inodes on unmount and get a busy inode crash from the VFS. Fix it by parking the cleaner before we actually close anything. Then, any remaining delayed iputs will always be handled in btrfs_commit_super(). This also ensures that the commit in close_ctree() is really the last commit, so we can get rid of the commit in cleaner_kthread(). The fstest/generic/475 followed by 476 can trigger a crash that manifests as a slab corruption caused by accessing the freed kthread structure by a wake up function. Sample trace: [ 5657.077612] BUG: unable to handle kernel NULL pointer dereference at 00000000000000cc [ 5657.079432] PGD 1c57a067 P4D 1c57a067 PUD da10067 PMD 0 [ 5657.080661] Oops: 0000 [#1] PREEMPT SMP [ 5657.081592] CPU: 1 PID: 5157 Comm: fsstress Tainted: G W 4.19.0-rc8-default+ #323 [ 5657.083703] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [ 5657.086577] RIP: 0010:shrink_page_list+0x2f9/0xe90 [ 5657.091937] RSP: 0018:ffffb5c745c8f728 EFLAGS: 00010287 [ 5657.092953] RAX: 0000000000000074 RBX: ffffb5c745c8f830 RCX: 0000000000000000 [ 5657.094590] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a8747fdf3d0 [ 5657.095987] RBP: ffffb5c745c8f9e0 R08: 0000000000000000 R09: 0000000000000000 [ 5657.097159] R10: ffff9a8747fdf5e8 R11: 0000000000000000 R12: ffffb5c745c8f788 [ 5657.098513] R13: ffff9a877f6ff2c0 R14: ffff9a877f6ff2c8 R15: dead000000000200 [ 5657.099689] FS: 00007f948d853b80(0000) GS:ffff9a877d600000(0000) knlGS:0000000000000000 [ 5657.101032] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5657.101953] CR2: 00000000000000cc CR3: 00000000684bd000 CR4: 00000000000006e0 [ 5657.103159] Call Trace: [ 5657.103776] shrink_inactive_list+0x194/0x410 [ 5657.104671] shrink_node_memcg.constprop.84+0x39a/0x6a0 [ 5657.105750] shrink_node+0x62/0x1c0 [ 5657.106529] try_to_free_pages+0x1a4/0x500 [ 5657.107408] __alloc_pages_slowpath+0x2c9/0xb20 [ 5657.108418] __alloc_pages_nodemask+0x268/0x2b0 [ 5657.109348] kmalloc_large_node+0x37/0x90 [ 5657.110205] __kmalloc_node+0x236/0x310 [ 5657.111014] kvmalloc_node+0x3e/0x70 Fixes: 30928e9baac2 ("btrfs: don't run delayed_iputs in commit") Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add trace ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-07ext4: fix buffer leak in ext4_expand_extra_isize_ea() on error pathVasily Averin
Fixes: de05ca852679 ("ext4: move call to ext4_error() into ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.17
2018-11-07ext4: fix buffer leak in ext4_xattr_move_to_block() on error pathVasily Averin
Fixes: 3f2571c1f91f ("ext4: factor out xattr moving") Fixes: 6dd4ee7cab7e ("ext4: Expand extra_inodes space per ...") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.23
2018-11-07ext4: release bs.bh before re-using in ext4_xattr_block_find()Vasily Averin
bs.bh was taken in previous ext4_xattr_block_find() call, it should be released before re-using Fixes: 7e01c8e5420b ("ext3/4: fix uninitialized bs in ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.26
2018-11-07ext4: fix buffer leak in ext4_xattr_get_block() on error pathVasily Averin
Fixes: dec214d00e0d ("ext4: xattr inode deduplication") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.13
2018-11-07ext4: fix possible leak of s_journal_flag_rwsem in error pathVasily Averin
Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.7
2018-11-07ext4: fix possible leak of sbi->s_group_desc_leak in error pathTheodore Ts'o
Fixes: bfe0a5f47ada ("ext4: add more mount time checks of the superblock") Reported-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.18
2018-11-06ext4: remove unneeded brelse call in ext4_xattr_inode_update_ref()Vasily Averin
Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-11-06ext4: avoid possible double brelse() in add_new_gdb() on error pathTheodore Ts'o
Fixes: b40971426a83 ("ext4: add error checking to calls to ...") Reported-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.38
2018-11-06ext4: avoid buffer leak in ext4_orphan_add() after prior errorsVasily Averin
Fixes: d745a8c20c1f ("ext4: reduce contention on s_orphan_lock") Fixes: 6e3617e579e0 ("ext4: Handle non empty on-disk orphan link") Cc: Dmitry Monakhov <dmonakhov@gmail.com> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.34
2018-11-06ext4: avoid buffer leak on shutdown in ext4_mark_iloc_dirty()Vasily Averin
ext4_mark_iloc_dirty() callers expect that it releases iloc->bh even if it returns an error. Fixes: 0db1ff222d40 ("ext4: add shutdown bit and check for it") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.11
2018-11-06ext4: fix possible inode leak in the retry loop of ext4_resize_fs()Vasily Averin
Fixes: 1c6bd7173d66 ("ext4: convert file system to meta_bg if needed ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.7