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authorLuis Henriques <lhenriques@suse.com>2017-05-17 12:21:07 +0100
committerIlya Dryomov <idryomov@gmail.com>2017-06-14 19:32:43 +0200
commit03f219041fdbeb31cecff41bb1cb4e1018f9cf75 (patch)
tree2c831e0e6149df0f676a419e8c90d1d5cd68dd41
parent32c1431eea4881a6b17bd7c639315010aeefa452 (diff)
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>
-rw-r--r--fs/ceph/export.c4
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);