lkml.org 
[lkml]   [2016]   [Mar]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.2.y-ckt 217/273] should_follow_link(): validate ->d_seq after having decided to follow
    Date
    4.2.8-ckt5 -stable review patch.  If anyone has any objections, please let me know.

    ---8<------------------------------------------------------------

    From: Al Viro <viro@zeniv.linux.org.uk>

    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: Kamal Mostafa <kamal@canonical.com>
    ---
    fs/namei.c | 5 +++++
    1 file changed, 5 insertions(+)

    diff --git a/fs/namei.c b/fs/namei.c
    index 1047096..414561f 100644
    --- a/fs/namei.c
    +++ b/fs/namei.c
    @@ -1714,6 +1714,11 @@ 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);
    }

    --
    2.7.0
    \
     
     \ /
      Last update: 2016-03-08 01:01    [W:2.554 / U:0.232 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site