kernel.git/fs/namei.c, branch linux-5.16.y

fsnotify: invalidate dcache before IN_DELETE event

2022-02-01T16:29:03Z

commit a37d9a17f099072fe4d3a9048b0321978707a918 upstream. Apparently, there are some applications that use IN_DELETE event as an invalidation mechanism and expect that if they try to open a file with the name reported with the delete event, that it should not contain the content of the deleted file. Commit 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify will have access to a positive dentry. This allowed a race where opening the deleted file via cached dentry is now possible after receiving the IN_DELETE event. To fix the regression, create a new hook fsnotify_delete() that takes the unlinked inode as an argument and use a helper d_delete_notify() to pin the inode, so we can pass it to fsnotify_delete() after d_delete(). Backporting hint: this regression is from v5.3. Although patch will apply with only trivial conflicts to v5.4 and v5.10, it won't build, because fsnotify_delete() implementation is different in each of those versions (see fsnotify_link()). A follow up patch will fix the fsnotify_unlink/rmdir() calls in pseudo filesystem that do not need to call d_delete(). Link: https://lore.kernel.org/r/20220120215305.282577-1-amir73il@gmail.com Reported-by: Ivan Delalande Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/ Fixes: 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

Merge tag 'locks-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

2021-11-01T16:06:53Z

Pull file locking updates from Jeff Layton: "Most of this is just follow-on cleanup work of documentation and comments from the mandatory locking removal in v5.15. The only real functional change is that LOCK_MAND flock() support is also being removed, as it has basically been non-functional since the v2.5 days" * tag 'locks-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: fs: remove leftover comments from mandatory locking removal locks: remove changelog comments docs: fs: locks.rst: update comment about mandatory file locking Documentation: remove reference to now removed mandatory-locking doc locks: remove LOCK_MAND flock lock support

fs: remove leftover comments from mandatory locking removal

2021-10-26T16:20:50Z

Stragglers from commit f7e33bdbd6d1 ("fs: remove mandatory file locking support"). Signed-off-by: Jeff Layton

putname(): IS_ERR_OR_NULL() is wrong here

2021-09-07T20:14:05Z

Mixing NULL and ERR_PTR() just in case is a Bad Idea(tm). For struct filename the former is wrong - failures are reported as ERR_PTR(...), not as NULL. Signed-off-by: Al Viro

namei: Standardize callers of filename_create()

2021-09-07T20:11:01Z

filename_create() has two variants, one which drops the caller's reference to filename (filename_create) and one which does not (__filename_create). This can be confusing as it's unusual to drop a caller's reference. Remove filename_create, rename __filename_create to filename_create, and convert all callers. Link: https://lore.kernel.org/linux-fsdevel/f6238254-35bd-7e97-5b27-21050c745874@oracle.com/ Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Stephen Brennan Signed-off-by: Al Viro

namei: Standardize callers of filename_lookup()

2021-09-07T20:07:47Z

filename_lookup() has two variants, one which drops the caller's reference to filename (filename_lookup), and one which does not (__filename_lookup). This can be confusing as it's unusual to drop a caller's reference. Remove filename_lookup, rename __filename_lookup to filename_lookup, and convert all callers. The cost is a few slightly longer functions, but the clarity is greater. [AV: consuming a reference is not at all unusual, actually; look at e.g. do_mkdirat(), for example. It's more that we want non-consuming variant for close relative of that function...] Link: https://lore.kernel.org/linux-fsdevel/YS+dstZ3xfcLxhoB@zeniv-ca.linux.org.uk/ Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Stephen Brennan Signed-off-by: Al Viro

rename __filename_parentat() to filename_parentat()

2021-09-07T19:57:42Z

... in separate commit, to avoid noise in previous one Signed-off-by: Al Viro

namei: Fix use after free in kern_path_locked

2021-09-07T19:56:16Z

In 0ee50b47532a ("namei: change filename_parentat() calling conventions"), filename_parentat() was made to always call putname() on the filename before returning, and kern_path_locked() was migrated to this calling convention. However, kern_path_locked() uses the "last" parameter to lookup and potentially create a new dentry. The last parameter contains the last component of the path and points within the filename, which was recently freed at the end of filename_parentat(). Thus, when kern_path_locked() calls __lookup_hash(), it is using the filename after it has already been freed. In other words, these calling conventions had been wrong for the only remaining caller of filename_parentat(). Everything else is using __filename_parentat(), which does not drop the reference; so should kern_path_locked(). Switch kern_path_locked() to use of __filename_parentat() and move getting/dropping struct filename into wrapper. Remove filename_parentat(), now that we have no remaining callers. Fixes: 0ee50b47532a ("namei: change filename_parentat() calling conventions") Link: https://lore.kernel.org/linux-fsdevel/YS9D4AlEsaCxLFV0@infradead.org/ Link: https://lore.kernel.org/linux-fsdevel/YS+csMTV2tTXKg3s@zeniv-ca.linux.org.uk/ Cc: Christoph Hellwig Cc: Al Viro Reported-by: syzbot+fb0d60a179096e8c2731@syzkaller.appspotmail.com Signed-off-by: Stephen Brennan Co-authored-by: Dmitry Kadashev Signed-off-by: Al Viro

Merge branch 'akpm' (patches from Andrew)

2021-09-03T17:08:28Z

Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton : (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...

fs, mm: fix race in unlinking swapfile

2021-09-03T16:58:11Z

We had a recurring situation in which admin procedures setting up swapfiles would race with test preparation clearing away swapfiles; and just occasionally that got stuck on a swapfile "(deleted)" which could never be swapped off. That is not supposed to be possible. 2.6.28 commit f9454548e17c ("don't unlink an active swapfile") admitted that it was leaving a race window open: now close it. may_delete() makes the IS_SWAPFILE check (amongst many others) before inode_lock has been taken on target: now repeat just that simple check in vfs_unlink() and vfs_rename(), after taking inode_lock. Which goes most of the way to fixing the race, but swapon() must also check after it acquires inode_lock, that the file just opened has not already been unlinked. Link: https://lkml.kernel.org/r/e17b91ad-a578-9a15-5e3-4989e0f999b5@google.com Fixes: f9454548e17c ("don't unlink an active swapfile") Signed-off-by: Hugh Dickins Reviewed-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds