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| author | Luis Henriques <lhenriques@suse.com> | 2017-05-17 13:21:07 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2017-06-14 19:32:43 +0200 |
| commit | 03f219041fdbeb31cecff41bb1cb4e1018f9cf75 (patch) | |
| tree | 2c831e0e6149df0f676a419e8c90d1d5cd68dd41 /fs | |
| parent | Linux 4.12-rc5 (diff) | |
| download | linux-03f219041fdbeb31cecff41bb1cb4e1018f9cf75.tar.xz linux-03f219041fdbeb31cecff41bb1cb4e1018f9cf75.zip | |
ceph: check i_nlink while converting a file handle to dentry
Converting a file handle to a dentry can be done call after the inode
unlink. This means that __fh_to_dentry() requires an extra check to
verify the number of links is not 0.
The issue can be easily reproduced using xfstest generic/426, which does
something like:
name_to_handle_at(&fh)
echo 3 > /proc/sys/vm/drop_caches
unlink()
open_by_handle_at(&fh)
The call to open_by_handle_at() should fail, as the file doesn't exist
anymore.
Link: http://tracker.ceph.com/issues/19958
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ceph/export.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ceph/export.c b/fs/ceph/export.c index e8f11fa565c5..7df550c13d7f 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -91,6 +91,10 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) ceph_mdsc_put_request(req); if (!inode) return ERR_PTR(-ESTALE); + if (inode->i_nlink == 0) { + iput(inode); + return ERR_PTR(-ESTALE); + } } return d_obtain_alias(inode); |