diff options
| author | Marc Dionne <marc.dionne@auristor.com> | 2024-05-24 18:17:55 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-05-25 14:02:40 +0200 |
| commit | 29be9100aca2915fab54b5693309bc42956542e5 (patch) | |
| tree | ed984039f37b960c0cba76fa9efe1b62c8f888c1 /fs/afs/mntpt.c | |
| parent | swap: yield device immediately (diff) | |
| download | linux-29be9100aca2915fab54b5693309bc42956542e5.tar.xz linux-29be9100aca2915fab54b5693309bc42956542e5.zip | |
afs: Don't cross .backup mountpoint from backup volume
Don't cross a mountpoint that explicitly specifies a backup volume
(target is <vol>.backup) when starting from a backup volume.
It it not uncommon to mount a volume's backup directly in the volume
itself. This can cause tools that are not paying attention to get
into a loop mounting the volume onto itself as they attempt to
traverse the tree, leading to a variety of problems.
This doesn't prevent the general case of loops in a sequence of
mountpoints, but addresses a common special case in the same way
as other afs clients.
Reported-by: Jan Henrik Sylvester <jan.henrik.sylvester@uni-hamburg.de>
Link: http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Link: http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/768760.1716567475@warthog.procyon.org.uk
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/afs/mntpt.c')
| -rw-r--r-- | fs/afs/mntpt.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index 97f50e9fd9eb..297487ee8323 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -140,6 +140,11 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) put_page(page); if (ret < 0) return ret; + + /* Don't cross a backup volume mountpoint from a backup volume */ + if (src_as->volume && src_as->volume->type == AFSVL_BACKVOL && + ctx->type == AFSVL_BACKVOL) + return -ENODEV; } return 0; |