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2019-08-16nfsd4: Fix kernel crash when reading proc file reply_cache_statsHe Zhe
reply_cache_stats uses wrong parameter as seq file private structure and thus causes the following kernel crash when users read /proc/fs/nfsd/reply_cache_stats BUG: kernel NULL pointer dereference, address: 00000000000001f9 PGD 0 P4D 0 Oops: 0000 [#3] SMP PTI CPU: 6 PID: 1502 Comm: cat Tainted: G D 5.3.0-rc3+ #1 Hardware name: Intel Corporation Broadwell Client platform/Basking Ridge, BIOS BDW-E2R1.86C.0118.R01.1503110618 03/11/2015 RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa520106fe08 EFLAGS: 00010246 RAX: 000000cfe1a77123 RBX: 0000000000000000 RCX: 0000000000291b46 RDX: 000000cf00000000 RSI: 0000000000000006 RDI: 0000000000291b28 RBP: ffffaa520106fe20 R08: 0000000000000006 R09: 000000cfe17e55dd R10: ffffa424e47c0000 R11: 000000000000030b R12: 0000000000000001 R13: ffffa424e5697000 R14: 0000000000000001 R15: ffffa424e5697000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Call Trace: seq_read+0x194/0x3e0 __vfs_read+0x1b/0x40 vfs_read+0x95/0x140 ksys_read+0x61/0xe0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f805728b861 Code: fe ff ff 50 48 8d 3d 86 b4 09 00 e8 79 e0 01 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 d9 19 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 48 83 ec 28 48 89 54 RSP: 002b:00007ffea1ce3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f805728b861 RDX: 0000000000020000 RSI: 00007f8057183000 RDI: 0000000000000003 RBP: 00007f8057183000 R08: 00007f8057182010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000559a60e8ff10 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 Modules linked in: CR2: 00000000000001f9 ---[ end trace 01613595153f0cba ]--- RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa52004b3e08 EFLAGS: 00010246 RAX: 0000002bab45a7c6 RBX: 0000000000000000 RCX: 0000000000291b4c RDX: 0000002b00000000 RSI: 0000000000000004 RDI: 0000000000291b28 RBP: ffffaa52004b3e20 R08: 0000000000000004 R09: 0000002bab1c8c7a R10: ffffa424e5500000 R11: 00000000000002a9 R12: 0000000000000001 R13: ffffa424e4475000 R14: 0000000000000001 R15: ffffa424e4475000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Killed Fixes: 3ba75830ce17 ("nfsd4: drc containerization") Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-16locks: print a warning when mount fails due to lack of "mand" supportJeff Layton
Since 9e8925b67a ("locks: Allow disabling mandatory locking at compile time"), attempts to mount filesystems with "-o mand" will fail. Unfortunately, there is no other indiciation of the reason for the failure. Change how the function is defined for better readability. When CONFIG_MANDATORY_FILE_LOCKING is disabled, printk a warning when someone attempts to mount with -o mand. Also, add a blurb to the mandatory-locking.txt file to explain about the "mand" option, and the behavior one should expect when it is disabled. Reported-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@kernel.org>
2019-08-15nfsd: initialize i_private before d_addJ. Bruce Fields
A process could race in an open and attempt to read one of these files before i_private is initialized, and get a spurious error. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-15writeback, cgroup: inode_switch_wbs() shouldn't give up on wb_switch_rwsem ↵Tejun Heo
trylock fail As inode wb switching may make sync(2) miss some inodes, they're synchronized using wb_switch_rwsem so that no wb switching happens while sync(2) is in progress. In addition to synchronizing the actual switching, the rwsem is also used to prevent queueing new switch attempts while sync(2) is in progress. This is to avoid queueing too many instances while the rwsem is held by sync(2). Unfortunately, this is too agressive and can block wb switching for a long time if sync(2) is frequent. The goal is avoiding expolding the number of scheduled switches, not avoiding scheduling anything. Let's use wb_switch_rwsem only for synchronizing the actual switching and sync(2) and use isw_nr_in_flight instead for limiting the maximum number of scheduled switches. The limit is set to 1024 which should be more than enough while still avoiding extreme situations. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-15writeback, cgroup: Adjust WB_FRN_TIME_CUT_DIV to accelerate foreign inode ↵Tejun Heo
switching WB_FRN_TIME_CUT_DIV is used to tell the foreign inode detection logic to ignore short writeback rounds to prevent getting confused by a burst of short writebacks. The parameter is currently 2 meaning that anything smaller than half of the running average writback duration will be ignored. This is unnecessarily aggressive. The detection logic uses 16 history slots and is already reasonably protected against some short bursts confusing it and the current parameter can lead to tens of seconds of missed detection depending on the writeback pattern. Let's change the parameter to 8, so that it only ignores writeback with are smaller than 12.5% of the current running average. v2: Add comment explaining what's going on with the foreign detection parameters. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-15Merge tag 'xfs-5.3-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Darrick Wong: - Fix crashes when the attr fork isn't present due to errors but inode inactivation tries to zap the attr data anyway. - Convert more directory corruption debugging asserts to actual EFSCORRUPTED returns instead of blowing up later on. - Don't fail writeback just because we ran out of memory allocating metadata log data. * tag 'xfs-5.3-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: don't crash on null attr fork xfs_bmapi_read xfs: remove more ondisk directory corruption asserts fs: xfs: xfs_log: Don't use KM_MAYFAIL at xfs_log_reserve().
2019-08-15nfsd: use i_wrlock instead of rcu for nfsdfs i_privateJ. Bruce Fields
synchronize_rcu() gets called multiple times each time a client is destroyed. If the laundromat thread has a lot of clients to destroy, the delay can be noticeable. This was causing pynfs test RENEW3 to fail. We could embed an rcu_head in each inode and do the kref_put in an rcu callback. But simplest is just to take a lock here. (I also wonder if the laundromat thread would be better replaced by a bunch of scheduled work or timers or something.) Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-15nfsd: fix dentry leak upon mkdir failure.Tetsuo Handa
syzbot is reporting that nfsd_mkdir() forgot to remove dentry created by d_alloc_name() when __nfsd_mkdir() failed (due to memory allocation fault injection) [1]. [1] https://syzkaller.appspot.com/bug?id=ce41a1f769ea4637ebffedf004a803e8405b4674 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+2c95195d5d433f6ed6cb@syzkaller.appspotmail.com> Fixes: e8a79fb14f6b76b5 ("nfsd: add nfsd/clients directory") [bfields: clean up in nfsd_mkdir instead of __nfsd_mkdir] Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-15io_uring: fix an issue when IOSQE_IO_LINK is inserted into defer listJackie Liu
This patch may fix two issues: First, when IOSQE_IO_DRAIN set, the next IOs need to be inserted into defer list to delay execution, but link io will be actively scheduled to run by calling io_queue_sqe. Second, when multiple LINK_IOs are inserted together with defer_list, the LINK_IO is no longer keep order. |-------------| | LINK_IO | ----> insert to defer_list ----------- |-------------| | | LINK_IO | ----> insert to defer_list ----------| |-------------| | | LINK_IO | ----> insert to defer_list ----------| |-------------| | | NORMAL_IO | ----> insert to defer_list ----------| |-------------| | | queue_work at same time <-----| Fixes: 9e645e1105c ("io_uring: add support for sqe links") Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-15block: remove REQ_NOWAIT_INLINEJens Axboe
We had a few issues with this code, and there's still a problem around how we deal with error handling for chained/split bios. For now, just revert the code and we'll try again with a thoroug solution. This reverts commits: e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments") 0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments") 6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO") 893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-15io_uring: fix manual setup of iov_iter for fixed buffersAleix Roca Nonell
Commit bd11b3a391e3 ("io_uring: don't use iov_iter_advance() for fixed buffers") introduced an optimization to avoid using the slow iov_iter_advance by manually populating the iov_iter iterator in some cases. However, the computation of the iterator count field was erroneous: The first bvec was always accounted for an extent of page size even if the bvec length was smaller. In consequence, some I/O operations on fixed buffers were unable to operate on the full extent of the buffer, consistently skipping some bytes at the end of it. Fixes: bd11b3a391e3 ("io_uring: don't use iov_iter_advance() for fixed buffers") Cc: stable@vger.kernel.org Signed-off-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-14Merge tag 'afs-fixes-20190814' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull afs fixes from David Howells: - Fix the CB.ProbeUuid handler to generate its reply correctly. - Fix a mix up in indices when parsing a Volume Location entry record. - Fix a potential NULL-pointer deref when cleaning up a read request. - Fix the expected data version of the destination directory in afs_rename(). - Fix afs_d_revalidate() to only update d_fsdata if it's not the same as the directory data version to reduce the likelihood of overwriting the result of a competing operation. (d_fsdata carries the directory DV or the least-significant word thereof). - Fix the tracking of the data-version on a directory and make sure that dentry objects get properly initialised, updated and revalidated. Also fix rename to update d_fsdata to match the new directory's DV if the dentry gets moved over and unhash the dentry to stop afs_d_revalidate() from interfering. * tag 'afs-fixes-20190814' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Fix missing dentry data version updating afs: Only update d_fsdata if different in afs_d_revalidate() afs: Fix off-by-one in afs_rename() expected data version calculation fs: afs: Fix a possible null-pointer dereference in afs_put_read() afs: Fix loop index mixup in afs_deliver_vl_get_entry_by_name_u() afs: Fix the CB.ProbeUuid service handler to reply correctly
2019-08-13seq_file: fix problem when seeking mid-recordNeilBrown
If you use lseek or similar (e.g. pread) to access a location in a seq_file file that is within a record, rather than at a record boundary, then the first read will return the remainder of the record, and the second read will return the whole of that same record (instead of the next record). When seeking to a record boundary, the next record is correctly returned. This bug was introduced by a recent patch (identified below). Before that patch, seq_read() would increment m->index when the last of the buffer was returned (m->count == 0). After that patch, we rely on ->next to increment m->index after filling the buffer - but there was one place where that didn't happen. Link: https://lkml.kernel.org/lkml/877e7xl029.fsf@notabene.neil.brown.name/ Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: NeilBrown <neilb@suse.com> Reported-by: Sergei Turchanov <turchanov@farpost.com> Tested-by: Sergei Turchanov <turchanov@farpost.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Markus Elfring <Markus.Elfring@web.de> Cc: <stable@vger.kernel.org> [4.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-12f2fs: add fs-verity supportEric Biggers
Add fs-verity support to f2fs. fs-verity is a filesystem feature that enables transparent integrity protection and authentication of read-only files. It uses a dm-verity like mechanism at the file level: a Merkle tree is used to verify any block in the file in log(filesize) time. It is implemented mainly by helper functions in fs/verity/. See Documentation/filesystems/fsverity.rst for the full documentation. The f2fs support for fs-verity consists of: - Adding a filesystem feature flag and an inode flag for fs-verity. - Implementing the fsverity_operations to support enabling verity on an inode and reading/writing the verity metadata. - Updating ->readpages() to verify data as it's read from verity files and to support reading verity metadata pages. - Updating ->write_begin(), ->write_end(), and ->writepages() to support writing verity metadata pages. - Calling the fs-verity hooks for ->open(), ->setattr(), and ->ioctl(). Like ext4, f2fs stores the verity metadata (Merkle tree and fsverity_descriptor) past the end of the file, starting at the first 64K boundary beyond i_size. This approach works because (a) verity files are readonly, and (b) pages fully beyond i_size aren't visible to userspace but can be read/written internally by f2fs with only some relatively small changes to f2fs. Extended attributes cannot be used because (a) f2fs limits the total size of an inode's xattr entries to 4096 bytes, which wouldn't be enough for even a single Merkle tree block, and (b) f2fs encryption doesn't encrypt xattrs, yet the verity metadata *must* be encrypted when the file is because it contains hashes of the plaintext data. Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> Acked-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12ext4: add fs-verity read supportEric Biggers
Make ext4_mpage_readpages() verify data as it is read from fs-verity files, using the helper functions from fs/verity/. To support both encryption and verity simultaneously, this required refactoring the decryption workflow into a generic "post-read processing" workflow which can do decryption, verification, or both. The case where the ext4 block size is not equal to the PAGE_SIZE is not supported yet, since in that case ext4_mpage_readpages() sometimes falls back to block_read_full_page(), which does not support fs-verity yet. Co-developed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12ext4: add basic fs-verity supportEric Biggers
Add most of fs-verity support to ext4. fs-verity is a filesystem feature that enables transparent integrity protection and authentication of read-only files. It uses a dm-verity like mechanism at the file level: a Merkle tree is used to verify any block in the file in log(filesize) time. It is implemented mainly by helper functions in fs/verity/. See Documentation/filesystems/fsverity.rst for the full documentation. This commit adds all of ext4 fs-verity support except for the actual data verification, including: - Adding a filesystem feature flag and an inode flag for fs-verity. - Implementing the fsverity_operations to support enabling verity on an inode and reading/writing the verity metadata. - Updating ->write_begin(), ->write_end(), and ->writepages() to support writing verity metadata pages. - Calling the fs-verity hooks for ->open(), ->setattr(), and ->ioctl(). ext4 stores the verity metadata (Merkle tree and fsverity_descriptor) past the end of the file, starting at the first 64K boundary beyond i_size. This approach works because (a) verity files are readonly, and (b) pages fully beyond i_size aren't visible to userspace but can be read/written internally by ext4 with only some relatively small changes to ext4. This approach avoids having to depend on the EA_INODE feature and on rearchitecturing ext4's xattr support to support paging multi-gigabyte xattrs into memory, and to support encrypting xattrs. Note that the verity metadata *must* be encrypted when the file is, since it contains hashes of the plaintext data. This patch incorporates work by Theodore Ts'o and Chandan Rajendra. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fs-verity: support builtin file signaturesEric Biggers
To meet some users' needs, add optional support for having fs-verity handle a portion of the authentication policy in the kernel. An ".fs-verity" keyring is created to which X.509 certificates can be added; then a sysctl 'fs.verity.require_signatures' can be set to cause the kernel to enforce that all fs-verity files contain a signature of their file measurement by a key in this keyring. See the "Built-in signature verification" section of Documentation/filesystems/fsverity.rst for the full documentation. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fs-verity: add SHA-512 supportEric Biggers
Add SHA-512 support to fs-verity. This is primarily a demonstration of the trivial changes needed to support a new hash algorithm in fs-verity; most users will still use SHA-256, due to the smaller space required to store the hashes. But some users may prefer SHA-512. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fs-verity: implement FS_IOC_MEASURE_VERITY ioctlEric Biggers
Add a function for filesystems to call to implement the FS_IOC_MEASURE_VERITY ioctl. This ioctl retrieves the file measurement that fs-verity calculated for the given file and is enforcing for reads; i.e., reads that don't match this hash will fail. This ioctl can be used for authentication or logging of file measurements in userspace. See the "FS_IOC_MEASURE_VERITY" section of Documentation/filesystems/fsverity.rst for the documentation. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fs-verity: implement FS_IOC_ENABLE_VERITY ioctlEric Biggers
Add a function for filesystems to call to implement the FS_IOC_ENABLE_VERITY ioctl. This ioctl enables fs-verity on a file. See the "FS_IOC_ENABLE_VERITY" section of Documentation/filesystems/fsverity.rst for the documentation. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12ubifs: wire up new fscrypt ioctlsEric Biggers
Wire up the new ioctls for adding and removing fscrypt keys to/from the filesystem, and the new ioctl for retrieving v2 encryption policies. The key removal ioctls also required making UBIFS use fscrypt_drop_inode(). For more details see Documentation/filesystems/fscrypt.rst and the fscrypt patches that added the implementation of these ioctls. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12f2fs: wire up new fscrypt ioctlsEric Biggers
Wire up the new ioctls for adding and removing fscrypt keys to/from the filesystem, and the new ioctl for retrieving v2 encryption policies. The key removal ioctls also required making f2fs_drop_inode() call fscrypt_drop_inode(). For more details see Documentation/filesystems/fscrypt.rst and the fscrypt patches that added the implementation of these ioctls. Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12ext4: wire up new fscrypt ioctlsEric Biggers
Wire up the new ioctls for adding and removing fscrypt keys to/from the filesystem, and the new ioctl for retrieving v2 encryption policies. The key removal ioctls also required making ext4_drop_inode() call fscrypt_drop_inode(). For more details see Documentation/filesystems/fscrypt.rst and the fscrypt patches that added the implementation of these ioctls. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: require that key be added when setting a v2 encryption policyEric Biggers
By looking up the master keys in a filesystem-level keyring rather than in the calling processes' key hierarchy, it becomes possible for a user to set an encryption policy which refers to some key they don't actually know, then encrypt their files using that key. Cryptographically this isn't much of a problem, but the semantics of this would be a bit weird. Thus, enforce that a v2 encryption policy can only be set if the user has previously added the key, or has capable(CAP_FOWNER). We tolerate that this problem will continue to exist for v1 encryption policies, however; there is no way around that. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctlEric Biggers
Add a root-only variant of the FS_IOC_REMOVE_ENCRYPTION_KEY ioctl which removes all users' claims of the key, not just the current user's claim. I.e., it always removes the key itself, no matter how many users have added it. This is useful for forcing a directory to be locked, without having to figure out which user ID(s) the key was added under. This is planned to be used by a command like 'sudo fscrypt lock DIR --all-users' in the fscrypt userspace tool (http://github.com/google/fscrypt). Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: allow unprivileged users to add/remove keys for v2 policiesEric Biggers
Allow the FS_IOC_ADD_ENCRYPTION_KEY and FS_IOC_REMOVE_ENCRYPTION_KEY ioctls to be used by non-root users to add and remove encryption keys from the filesystem-level crypto keyrings, subject to limitations. Motivation: while privileged fscrypt key management is sufficient for some users (e.g. Android and Chromium OS, where a privileged process manages all keys), the old API by design also allows non-root users to set up and use encrypted directories, and we don't want to regress on that. Especially, we don't want to force users to continue using the old API, running into the visibility mismatch between files and keyrings and being unable to "lock" encrypted directories. Intuitively, the ioctls have to be privileged since they manipulate filesystem-level state. However, it's actually safe to make them unprivileged if we very carefully enforce some specific limitations. First, each key must be identified by a cryptographic hash so that a user can't add the wrong key for another user's files. For v2 encryption policies, we use the key_identifier for this. v1 policies don't have this, so managing keys for them remains privileged. Second, each key a user adds is charged to their quota for the keyrings service. Thus, a user can't exhaust memory by adding a huge number of keys. By default each non-root user is allowed up to 200 keys; this can be changed using the existing sysctl 'kernel.keys.maxkeys'. Third, if multiple users add the same key, we keep track of those users of the key (of which there remains a single copy), and won't really remove the key, i.e. "lock" the encrypted files, until all those users have removed it. This prevents denial of service attacks that would be possible under simpler schemes, such allowing the first user who added a key to remove it -- since that could be a malicious user who has compromised the key. Of course, encryption keys should be kept secret, but the idea is that using encryption should never be *less* secure than not using encryption, even if your key was compromised. We tolerate that a user will be unable to really remove a key, i.e. unable to "lock" their encrypted files, if another user has added the same key. But in a sense, this is actually a good thing because it will avoid providing a false notion of security where a key appears to have been removed when actually it's still in memory, available to any attacker who compromises the operating system kernel. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: v2 encryption policy supportEric Biggers
Add a new fscrypt policy version, "v2". It has the following changes from the original policy version, which we call "v1" (*): - Master keys (the user-provided encryption keys) are only ever used as input to HKDF-SHA512. This is more flexible and less error-prone, and it avoids the quirks and limitations of the AES-128-ECB based KDF. Three classes of cryptographically isolated subkeys are defined: - Per-file keys, like used in v1 policies except for the new KDF. - Per-mode keys. These implement the semantics of the DIRECT_KEY flag, which for v1 policies made the master key be used directly. These are also planned to be used for inline encryption when support for it is added. - Key identifiers (see below). - Each master key is identified by a 16-byte master_key_identifier, which is derived from the key itself using HKDF-SHA512. This prevents users from associating the wrong key with an encrypted file or directory. This was easily possible with v1 policies, which identified the key by an arbitrary 8-byte master_key_descriptor. - The key must be provided in the filesystem-level keyring, not in a process-subscribed keyring. The following UAPI additions are made: - The existing ioctl FS_IOC_SET_ENCRYPTION_POLICY can now be passed a fscrypt_policy_v2 to set a v2 encryption policy. It's disambiguated from fscrypt_policy/fscrypt_policy_v1 by the version code prefix. - A new ioctl FS_IOC_GET_ENCRYPTION_POLICY_EX is added. It allows getting the v1 or v2 encryption policy of an encrypted file or directory. The existing FS_IOC_GET_ENCRYPTION_POLICY ioctl could not be used because it did not have a way for userspace to indicate which policy structure is expected. The new ioctl includes a size field, so it is extensible to future fscrypt policy versions. - The ioctls FS_IOC_ADD_ENCRYPTION_KEY, FS_IOC_REMOVE_ENCRYPTION_KEY, and FS_IOC_GET_ENCRYPTION_KEY_STATUS now support managing keys for v2 encryption policies. Such keys are kept logically separate from keys for v1 encryption policies, and are identified by 'identifier' rather than by 'descriptor'. The 'identifier' need not be provided when adding a key, since the kernel will calculate it anyway. This patch temporarily keeps adding/removing v2 policy keys behind the same permission check done for adding/removing v1 policy keys: capable(CAP_SYS_ADMIN). However, the next patch will carefully take advantage of the cryptographically secure master_key_identifier to allow non-root users to add/remove v2 policy keys, thus providing a full replacement for v1 policies. (*) Actually, in the API fscrypt_policy::version is 0 while on-disk fscrypt_context::format is 1. But I believe it makes the most sense to advance both to '2' to have them be in sync, and to consider the numbering to start at 1 except for the API quirk. Reviewed-by: Paul Crowley <paulcrowley@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add an HKDF-SHA512 implementationEric Biggers
Add an implementation of HKDF (RFC 5869) to fscrypt, for the purpose of deriving additional key material from the fscrypt master keys for v2 encryption policies. HKDF is a key derivation function built on top of HMAC. We choose SHA-512 for the underlying unkeyed hash, and use an "hmac(sha512)" transform allocated from the crypto API. We'll be using this to replace the AES-ECB based KDF currently used to derive the per-file encryption keys. While the AES-ECB based KDF is believed to meet the original security requirements, it is nonstandard and has problems that don't exist in modern KDFs such as HKDF: 1. It's reversible. Given a derived key and nonce, an attacker can easily compute the master key. This is okay if the master key and derived keys are equally hard to compromise, but now we'd like to be more robust against threats such as a derived key being compromised through a timing attack, or a derived key for an in-use file being compromised after the master key has already been removed. 2. It doesn't evenly distribute the entropy from the master key; each 16 input bytes only affects the corresponding 16 output bytes. 3. It isn't easily extensible to deriving other values or keys, such as a public hash for securely identifying the key, or per-mode keys. Per-mode keys will be immediately useful for Adiantum encryption, for which fscrypt currently uses the master key directly, introducing unnecessary usage constraints. Per-mode keys will also be useful for hardware inline encryption, which is currently being worked on. HKDF solves all the above problems. Reviewed-by: Paul Crowley <paulcrowley@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctlEric Biggers
Add a new fscrypt ioctl, FS_IOC_GET_ENCRYPTION_KEY_STATUS. Given a key specified by 'struct fscrypt_key_specifier' (the same way a key is specified for the other fscrypt key management ioctls), it returns status information in a 'struct fscrypt_get_key_status_arg'. The main motivation for this is that applications need to be able to check whether an encrypted directory is "unlocked" or not, so that they can add the key if it is not, and avoid adding the key (which may involve prompting the user for a passphrase) if it already is. It's possible to use some workarounds such as checking whether opening a regular file fails with ENOKEY, or checking whether the filenames "look like gibberish" or not. However, no workaround is usable in all cases. Like the other key management ioctls, the keyrings syscalls may seem at first to be a good fit for this. Unfortunately, they are not. Even if we exposed the keyring ID of the ->s_master_keys keyring and gave everyone Search permission on it (note: currently the keyrings permission system would also allow everyone to "invalidate" the keyring too), the fscrypt keys have an additional state that doesn't map cleanly to the keyrings API: the secret can be removed, but we can be still tracking the files that were using the key, and the removal can be re-attempted or the secret added again. After later patches, some applications will also need a way to determine whether a key was added by the current user vs. by some other user. Reserved fields are included in fscrypt_get_key_status_arg for this and other future extensions. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctlEric Biggers
Add a new fscrypt ioctl, FS_IOC_REMOVE_ENCRYPTION_KEY. This ioctl removes an encryption key that was added by FS_IOC_ADD_ENCRYPTION_KEY. It wipes the secret key itself, then "locks" the encrypted files and directories that had been unlocked using that key -- implemented by evicting the relevant dentries and inodes from the VFS caches. The problem this solves is that many fscrypt users want the ability to remove encryption keys, causing the corresponding encrypted directories to appear "locked" (presented in ciphertext form) again. Moreover, users want removing an encryption key to *really* remove it, in the sense that the removed keys cannot be recovered even if kernel memory is compromised, e.g. by the exploit of a kernel security vulnerability or by a physical attack. This is desirable after a user logs out of the system, for example. In many cases users even already assume this to be the case and are surprised to hear when it's not. It is not sufficient to simply unlink the master key from the keyring (or to revoke or invalidate it), since the actual encryption transform objects are still pinned in memory by their inodes. Therefore, to really remove a key we must also evict the relevant inodes. Currently one workaround is to run 'sync && echo 2 > /proc/sys/vm/drop_caches'. But, that evicts all unused inodes in the system rather than just the inodes associated with the key being removed, causing severe performance problems. Moreover, it requires root privileges, so regular users can't "lock" their encrypted files. Another workaround, used in Chromium OS kernels, is to add a new VFS-level ioctl FS_IOC_DROP_CACHE which is a more restricted version of drop_caches that operates on a single super_block. It does: shrink_dcache_sb(sb); invalidate_inodes(sb, false); But it's still a hack. Yet, the major users of filesystem encryption want this feature badly enough that they are actually using these hacks. To properly solve the problem, start maintaining a list of the inodes which have been "unlocked" using each master key. Originally this wasn't possible because the kernel didn't keep track of in-use master keys at all. But, with the ->s_master_keys keyring it is now possible. Then, add an ioctl FS_IOC_REMOVE_ENCRYPTION_KEY. It finds the specified master key in ->s_master_keys, then wipes the secret key itself, which prevents any additional inodes from being unlocked with the key. Then, it syncs the filesystem and evicts the inodes in the key's list. The normal inode eviction code will free and wipe the per-file keys (in ->i_crypt_info). Note that freeing ->i_crypt_info without evicting the inodes was also considered, but would have been racy. Some inodes may still be in use when a master key is removed, and we can't simply revoke random file descriptors, mmap's, etc. Thus, the ioctl simply skips in-use inodes, and returns -EBUSY to indicate that some inodes weren't evicted. The master key *secret* is still removed, but the fscrypt_master_key struct remains to keep track of the remaining inodes. Userspace can then retry the ioctl to evict the remaining inodes. Alternatively, if userspace adds the key again, the refreshed secret will be associated with the existing list of inodes so they remain correctly tracked for future key removals. The ioctl doesn't wipe pagecache pages. Thus, we tolerate that after a kernel compromise some portions of plaintext file contents may still be recoverable from memory. This can be solved by enabling page poisoning system-wide, which security conscious users may choose to do. But it's very difficult to solve otherwise, e.g. note that plaintext file contents may have been read in other places than pagecache pages. Like FS_IOC_ADD_ENCRYPTION_KEY, FS_IOC_REMOVE_ENCRYPTION_KEY is initially restricted to privileged users only. This is sufficient for some use cases, but not all. A later patch will relax this restriction, but it will require introducing key hashes, among other changes. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctlEric Biggers
Add a new fscrypt ioctl, FS_IOC_ADD_ENCRYPTION_KEY. This ioctl adds an encryption key to the filesystem's fscrypt keyring ->s_master_keys, making any files encrypted with that key appear "unlocked". Why we need this ~~~~~~~~~~~~~~~~ The main problem is that the "locked/unlocked" (ciphertext/plaintext) status of encrypted files is global, but the fscrypt keys are not. fscrypt only looks for keys in the keyring(s) the process accessing the filesystem is subscribed to: the thread keyring, process keyring, and session keyring, where the session keyring may contain the user keyring. Therefore, userspace has to put fscrypt keys in the keyrings for individual users or sessions. But this means that when a process with a different keyring tries to access encrypted files, whether they appear "unlocked" or not is nondeterministic. This is because it depends on whether the files are currently present in the inode cache. Fixing this by consistently providing each process its own view of the filesystem depending on whether it has the key or not isn't feasible due to how the VFS caches work. Furthermore, while sometimes users expect this behavior, it is misguided for two reasons. First, it would be an OS-level access control mechanism largely redundant with existing access control mechanisms such as UNIX file permissions, ACLs, LSMs, etc. Encryption is actually for protecting the data at rest. Second, almost all users of fscrypt actually do need the keys to be global. The largest users of fscrypt, Android and Chromium OS, achieve this by having PID 1 create a "session keyring" that is inherited by every process. This works, but it isn't scalable because it prevents session keyrings from being used for any other purpose. On general-purpose Linux distros, the 'fscrypt' userspace tool [1] can't similarly abuse the session keyring, so to make 'sudo' work on all systems it has to link all the user keyrings into root's user keyring [2]. This is ugly and raises security concerns. Moreover it can't make the keys available to system services, such as sshd trying to access the user's '~/.ssh' directory (see [3], [4]) or NetworkManager trying to read certificates from the user's home directory (see [5]); or to Docker containers (see [6], [7]). By having an API to add a key to the *filesystem* we'll be able to fix the above bugs, remove userspace workarounds, and clearly express the intended semantics: the locked/unlocked status of an encrypted directory is global, and encryption is orthogonal to OS-level access control. Why not use the add_key() syscall ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We use an ioctl for this API rather than the existing add_key() system call because the ioctl gives us the flexibility needed to implement fscrypt-specific semantics that will be introduced in later patches: - Supporting key removal with the semantics such that the secret is removed immediately and any unused inodes using the key are evicted; also, the eviction of any in-use inodes can be retried. - Calculating a key-dependent cryptographic identifier and returning it to userspace. - Allowing keys to be added and removed by non-root users, but only keys for v2 encryption policies; and to prevent denial-of-service attacks, users can only remove keys they themselves have added, and a key is only really removed after all users who added it have removed it. Trying to shoehorn these semantics into the keyrings syscalls would be very difficult, whereas the ioctls make things much easier. However, to reuse code the implementation still uses the keyrings service internally. Thus we get lockless RCU-mode key lookups without having to re-implement it, and the keys automatically show up in /proc/keys for debugging purposes. References: [1] https://github.com/google/fscrypt [2] https://goo.gl/55cCrI#heading=h.vf09isp98isb [3] https://github.com/google/fscrypt/issues/111#issuecomment-444347939 [4] https://github.com/google/fscrypt/issues/116 [5] https://bugs.launchpad.net/ubuntu/+source/fscrypt/+bug/1770715 [6] https://github.com/google/fscrypt/issues/128 [7] https://askubuntu.com/questions/1130306/cannot-run-docker-on-an-encrypted-filesystem Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: rename keyinfo.c to keysetup.cEric Biggers
Rename keyinfo.c to keysetup.c since this better describes what the file does (sets up the key), and it matches the new file keysetup_v1.c. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: move v1 policy key setup to keysetup_v1.cEric Biggers
In preparation for introducing v2 encryption policies which will find and derive encryption keys differently from the current v1 encryption policies, move the v1 policy-specific key setup code from keyinfo.c into keysetup_v1.c. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: refactor key setup code in preparation for v2 policiesEric Biggers
Do some more refactoring of the key setup code, in preparation for introducing a filesystem-level keyring and v2 encryption policies: - Now that ci_inode exists, don't pass around the inode unnecessarily. - Define a function setup_file_encryption_key() which handles the crypto key setup given an under-construction fscrypt_info. Don't pass the fscrypt_context, since everything is in the fscrypt_info. [This will be extended for v2 policies and the fs-level keyring.] - Define a function fscrypt_set_derived_key() which sets the per-file key, without depending on anything specific to v1 policies. [This will also be used for v2 policies.] - Define a function fscrypt_setup_v1_file_key() which takes the raw master key, thus separating finding the key from using it. [This will also be used if the key is found in the fs-level keyring.] Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: rename fscrypt_master_key to fscrypt_direct_keyEric Biggers
In preparation for introducing a filesystem-level keyring which will contain fscrypt master keys, rename the existing 'struct fscrypt_master_key' to 'struct fscrypt_direct_key'. This is the structure in the existing table of master keys that's maintained to deduplicate the crypto transforms for v1 DIRECT_KEY policies. I've chosen to keep this table as-is rather than make it automagically add/remove the keys to/from the filesystem-level keyring, since that would add a lot of extra complexity to the filesystem-level keyring. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: add ->ci_inode to fscrypt_infoEric Biggers
Add an inode back-pointer to 'struct fscrypt_info', such that inode->i_crypt_info->ci_inode == inode. This will be useful for: 1. Evicting the inodes when a fscrypt key is removed, since we'll track the inodes using a given key by linking their fscrypt_infos together, rather than the inodes directly. This avoids bloating 'struct inode' with a new list_head. 2. Simplifying the per-file key setup, since the inode pointer won't have to be passed around everywhere just in case something goes wrong and it's needed for fscrypt_warn(). Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: use FSCRYPT_* definitions, not FS_*Eric Biggers
Update fs/crypto/ to use the new names for the UAPI constants rather than the old names, then make the old definitions conditional on !__KERNEL__. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: use ENOPKG when crypto API support missingEric Biggers
Return ENOPKG rather than ENOENT when trying to open a file that's encrypted using algorithms not available in the kernel's crypto API. This avoids an ambiguity, since ENOENT is also returned when the file doesn't exist. Note: this is the same approach I'm taking for fs-verity. Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: improve warnings for missing crypto API supportEric Biggers
Users of fscrypt with non-default algorithms will encounter an error like the following if they fail to include the needed algorithms into the crypto API when configuring the kernel (as per the documentation): Error allocating 'adiantum(xchacha12,aes)' transform: -2 This requires that the user figure out what the "-2" error means. Make it more friendly by printing a warning like the following instead: Missing crypto API support for Adiantum (API name: "adiantum(xchacha12,aes)") Also upgrade the log level for *other* errors to KERN_ERR. Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: improve warning messages for unsupported encryption contextsEric Biggers
When fs/crypto/ encounters an inode with an invalid encryption context, currently it prints a warning if the pair of encryption modes are unrecognized, but it's silent if there are other problems such as unsupported context size, format, or flags. To help people debug such situations, add more warning messages. Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: make fscrypt_msg() take inode instead of super_blockEric Biggers
Most of the warning and error messages in fs/crypto/ are for situations related to a specific inode, not merely to a super_block. So to make things easier, make fscrypt_msg() take an inode rather than a super_block, and make it print the inode number. Note: This is the same approach I'm taking for fsverity_msg(). Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: clean up base64 encoding/decodingEric Biggers
Some minor cleanups for the code that base64 encodes and decodes encrypted filenames and long name digests: - Rename "digest_{encode,decode}()" => "base64_{encode,decode}()" since they are used for filenames too, not just for long name digests. - Replace 'while' loops with more conventional 'for' loops. - Use 'u8' for binary data. Keep 'char' for string data. - Fully constify the lookup table (pointer was not const). - Improve comment. No actual change in behavior. Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fscrypt: remove loadable module related codeEric Biggers
Since commit 643fa9612bf1 ("fscrypt: remove filesystem specific build config option"), fs/crypto/ can no longer be built as a loadable module. Thus it no longer needs a module_exit function, nor a MODULE_LICENSE. So remove them, and change module_init to late_initcall. Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12fanotify, inotify, dnotify, security: add security hook for fs notificationsAaron Goidel
As of now, setting watches on filesystem objects has, at most, applied a check for read access to the inode, and in the case of fanotify, requires CAP_SYS_ADMIN. No specific security hook or permission check has been provided to control the setting of watches. Using any of inotify, dnotify, or fanotify, it is possible to observe, not only write-like operations, but even read access to a file. Modeling the watch as being merely a read from the file is insufficient for the needs of SELinux. This is due to the fact that read access should not necessarily imply access to information about when another process reads from a file. Furthermore, fanotify watches grant more power to an application in the form of permission events. While notification events are solely, unidirectional (i.e. they only pass information to the receiving application), permission events are blocking. Permission events make a request to the receiving application which will then reply with a decision as to whether or not that action may be completed. This causes the issue of the watching application having the ability to exercise control over the triggering process. Without drawing a distinction within the permission check, the ability to read would imply the greater ability to control an application. Additionally, mount and superblock watches apply to all files within the same mount or superblock. Read access to one file should not necessarily imply the ability to watch all files accessed within a given mount or superblock. In order to solve these issues, a new LSM hook is implemented and has been placed within the system calls for marking filesystem objects with inotify, fanotify, and dnotify watches. These calls to the hook are placed at the point at which the target path has been resolved and are provided with the path struct, the mask of requested notification events, and the type of object on which the mark is being set (inode, superblock, or mount). The mask and obj_type have already been translated into common FS_* values shared by the entirety of the fs notification infrastructure. The path struct is passed rather than just the inode so that the mount is available, particularly for mount watches. This also allows for use of the hook by pathname-based security modules. However, since the hook is intended for use even by inode based security modules, it is not placed under the CONFIG_SECURITY_PATH conditional. Otherwise, the inode-based security modules would need to enable all of the path hooks, even though they do not use any of them. This only provides a hook at the point of setting a watch, and presumes that permission to set a particular watch implies the ability to receive all notification about that object which match the mask. This is all that is required for SELinux. If other security modules require additional hooks or infrastructure to control delivery of notification, these can be added by them. It does not make sense for us to propose hooks for which we have no implementation. The understanding that all notifications received by the requesting application are all strictly of a type for which the application has been granted permission shows that this implementation is sufficient in its coverage. Security modules wishing to provide complete control over fanotify must also implement a security_file_open hook that validates that the access requested by the watching application is authorized. Fanotify has the issue that it returns a file descriptor with the file mode specified during fanotify_init() to the watching process on event. This is already covered by the LSM security_file_open hook if the security module implements checking of the requested file mode there. Otherwise, a watching process can obtain escalated access to a file for which it has not been authorized. The selinux_path_notify hook implementation works by adding five new file permissions: watch, watch_mount, watch_sb, watch_reads, and watch_with_perm (descriptions about which will follow), and one new filesystem permission: watch (which is applied to superblock checks). The hook then decides which subset of these permissions must be held by the requesting application based on the contents of the provided mask and the obj_type. The selinux_file_open hook already checks the requested file mode and therefore ensures that a watching process cannot escalate its access through fanotify. The watch, watch_mount, and watch_sb permissions are the baseline permissions for setting a watch on an object and each are a requirement for any watch to be set on a file, mount, or superblock respectively. It should be noted that having either of the other two permissions (watch_reads and watch_with_perm) does not imply the watch, watch_mount, or watch_sb permission. Superblock watches further require the filesystem watch permission to the superblock. As there is no labeled object in view for mounts, there is no specific check for mount watches beyond watch_mount to the inode. Such a check could be added in the future, if a suitable labeled object existed representing the mount. The watch_reads permission is required to receive notifications from read-exclusive events on filesystem objects. These events include accessing a file for the purpose of reading and closing a file which has been opened read-only. This distinction has been drawn in order to provide a direct indication in the policy for this otherwise not obvious capability. Read access to a file should not necessarily imply the ability to observe read events on a file. Finally, watch_with_perm only applies to fanotify masks since it is the only way to set a mask which allows for the blocking, permission event. This permission is needed for any watch which is of this type. Though fanotify requires CAP_SYS_ADMIN, this is insufficient as it gives implicit trust to root, which we do not do, and does not support least privilege. Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-08-12ext4: set error return correctly when ext4_htree_store_dirent failsColin Ian King
Currently when the call to ext4_htree_store_dirent fails the error return variable 'ret' is is not being set to the error code and variable count is instead, hence the error code is not being returned. Fix this by assigning ret to the error return code. Addresses-Coverity: ("Unused value") Fixes: 8af0f0822797 ("ext4: fix readdir error in the case of inline_data+dir_index") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-08-12ext4: drop legacy pre-1970 encoding workaroundTheodore Ts'o
Originally, support for expanded timestamps had a bug in that pre-1970 times were erroneously encoded as being in the the 24th century. This was fixed in commit a4dad1ae24f8 ("ext4: Fix handling of extended tv_sec") which landed in 4.4. Starting with 4.4, pre-1970 timestamps were correctly encoded, but for backwards compatibility those incorrectly encoded timestamps were mapped back to the pre-1970 dates. Given that backwards compatibility workaround has been around for 4 years, and given that running e2fsck from e2fsprogs 1.43.2 and later will offer to fix these timestamps (which has been released for 3 years), it's past time to drop the legacy workaround from the kernel. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-08-12xfs: don't crash on null attr fork xfs_bmapi_readDarrick J. Wong
Zorro Lang reported a crash in generic/475 if we try to inactivate a corrupt inode with a NULL attr fork (stack trace shortened somewhat): RIP: 0010:xfs_bmapi_read+0x311/0xb00 [xfs] RSP: 0018:ffff888047f9ed68 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888047f9f038 RCX: 1ffffffff5f99f51 RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000012 RBP: ffff888002a41f00 R08: ffffed10005483f0 R09: ffffed10005483ef R10: ffffed10005483ef R11: ffff888002a41f7f R12: 0000000000000004 R13: ffffe8fff53b5768 R14: 0000000000000005 R15: 0000000000000001 FS: 00007f11d44b5b80(0000) GS:ffff888114200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000ef6000 CR3: 000000002e176003 CR4: 00000000001606e0 Call Trace: xfs_dabuf_map.constprop.18+0x696/0xe50 [xfs] xfs_da_read_buf+0xf5/0x2c0 [xfs] xfs_da3_node_read+0x1d/0x230 [xfs] xfs_attr_inactive+0x3cc/0x5e0 [xfs] xfs_inactive+0x4c8/0x5b0 [xfs] xfs_fs_destroy_inode+0x31b/0x8e0 [xfs] destroy_inode+0xbc/0x190 xfs_bulkstat_one_int+0xa8c/0x1200 [xfs] xfs_bulkstat_one+0x16/0x20 [xfs] xfs_bulkstat+0x6fa/0xf20 [xfs] xfs_ioc_bulkstat+0x182/0x2b0 [xfs] xfs_file_ioctl+0xee0/0x12a0 [xfs] do_vfs_ioctl+0x193/0x1000 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x6f/0xb0 do_syscall_64+0x9f/0x4d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f11d39a3e5b The "obvious" cause is that the attr ifork is null despite the inode claiming an attr fork having at least one extent, but it's not so obvious why we ended up with an inode in that state. Reported-by: Zorro Lang <zlang@redhat.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204031 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com>
2019-08-12xfs: remove more ondisk directory corruption assertsDarrick J. Wong
Continue our game of replacing ASSERTs for corrupt ondisk metadata with EFSCORRUPTED returns. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com>
2019-08-12Merge 5.3-rc4 into driver-core-nextGreg Kroah-Hartman
We need the driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-11ext4: add new ioctl EXT4_IOC_GET_ES_CACHETheodore Ts'o
For debugging reasons, it's useful to know the contents of the extent cache. Since the extent cache contains much of what is in the fiemap ioctl, use an fiemap-style interface to return this information. Signed-off-by: Theodore Ts'o <tytso@mit.edu>