diff options
| author |   David Howells <dhowells@redhat.com> | 2022-06-21 15:59:57 +0100 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-29 08:58:46 +0200 |
| commit | e3a232e5767051483ffad4cef7d0a89d292a192b (patch) | |
| tree | 43045705840b7176ea9d9207fae765b5b1ca5f3d | |
| parent | MIPS: Remove repetitive increase irq_err_count (diff) | |
| download | wireguard-linux-e3a232e5767051483ffad4cef7d0a89d292a192b.tar.xz wireguard-linux-e3a232e5767051483ffad4cef7d0a89d292a192b.zip | |
afs: Fix dynamic root getattr
[ Upstream commit cb78d1b5efffe4cf97e16766329dd7358aed3deb ]
The recent patch to make afs_getattr consult the server didn't account
for the pseudo-inodes employed by the dynamic root-type afs superblock
not having a volume or a server to access, and thus an oops occurs if
such a directory is stat'd.
Fix this by checking to see if the vnode->volume pointer actually points
anywhere before following it in afs_getattr().
This can be tested by stat'ing a directory in /afs. It may be
sufficient just to do "ls /afs" and the oops looks something like:
BUG: kernel NULL pointer dereference, address: 0000000000000020
...
RIP: 0010:afs_getattr+0x8b/0x14b
...
Call Trace:
<TASK>
vfs_statx+0x79/0xf5
vfs_fstatat+0x49/0x62
Fixes: 2aeb8c86d499 ("afs: Fix afs_getattr() to refetch file status if callback break occurred")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/165408450783.1031787.7941404776393751186.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/afs/inode.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 90eac3ec01cb..622363af4c1b 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -739,7 +739,8 @@ int afs_getattr(const struct path *path, struct kstat *stat, _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); - if (!(query_flags & AT_STATX_DONT_SYNC) && + if (vnode->volume && + !(query_flags & AT_STATX_DONT_SYNC) && !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { key = afs_request_key(vnode->volume->cell); if (IS_ERR(key)) |