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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-02-27 19:31:01 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-02-27 19:31:01 -0500 |
| commit | a7f775428b8f5808815c0e3004020cedb94cbe3b (patch) | |
| tree | 44e2bed48f96a5e9918280e518448daab65ea44f /fs/namei.c | |
| parent | d4565649b6d6923369112758212b851adc407f0c (diff) | |
| download | lwn-a7f775428b8f5808815c0e3004020cedb94cbe3b.tar.gz lwn-a7f775428b8f5808815c0e3004020cedb94cbe3b.zip | |
should_follow_link(): validate ->d_seq after having decided to follow
... otherwise d_is_symlink() above might have nothing to do with
the inode value we've got.
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c index e0881c0bd228..65a0e9d1ea48 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1712,6 +1712,11 @@ static inline int should_follow_link(struct nameidata *nd, struct path *link, return 0; if (!follow) return 0; + /* make sure that d_is_symlink above matches inode */ + if (nd->flags & LOOKUP_RCU) { + if (read_seqcount_retry(&link->dentry->d_seq, seq)) + return -ECHILD; + } return pick_link(nd, link, inode, seq); } |