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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-02-27 19:31:01 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-03 15:07:30 -0800 |
| commit | 6f4b352f004c696439c5b5d75a4edc3d0823e770 (patch) | |
| tree | ca8990d3869be4dc536fa712892e05b1e0c268e7 /fs/namei.c | |
| parent | 9108b130f74d13a37e67a96cc0a8642464578a0a (diff) | |
| download | lwn-6f4b352f004c696439c5b5d75a4edc3d0823e770.tar.gz lwn-6f4b352f004c696439c5b5d75a4edc3d0823e770.zip | |
should_follow_link(): validate ->d_seq after having decided to follow
commit a7f775428b8f5808815c0e3004020cedb94cbe3b upstream.
... otherwise d_is_symlink() above might have nothing to do with
the inode value we've got.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 f26cecbd6e73..930b51d6308b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1711,6 +1711,11 @@ 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); } |