The patch titled
Subject: autofs: drop dentry reference only when it is never used
has been added to the -mm tree. Its filename is
autofs-drop-dentry-reference-only-when-it-is-never-used.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/autofs-drop-dentry-reference-only-when-it-is-never-used.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/autofs-drop-dentry-reference-only-when-it-is-never-used.patch
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------------------------------------------------------
From: Pan Bian <bianpan2016@xxxxxxx>
Subject: autofs: drop dentry reference only when it is never used
autofs_expire_run() calls dput(dentry) to drop the reference count of
dentry. However, dentry is read via autofs_dentry_ino(dentry) after that.
This may result in a use-free-bug. The patch drops the reference count
of dentry only when it is never used.
Link: http://lkml.kernel.org/r/154725122396.11260.16053424107144453867.stgit@pluto-themaw-net
Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/autofs/expire.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/autofs/expire.c~autofs-drop-dentry-reference-only-when-it-is-never-used
+++ a/fs/autofs/expire.c
@@ -596,7 +596,6 @@ int autofs_expire_run(struct super_block
pkt.len = dentry->d_name.len;
memcpy(pkt.name, dentry->d_name.name, pkt.len);
pkt.name[pkt.len] = '\0';
- dput(dentry);
if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
ret = -EFAULT;
@@ -609,6 +608,8 @@ int autofs_expire_run(struct super_block
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
+ dput(dentry);
+
return ret;
}
_
Patches currently in -mm which might be from bianpan2016@xxxxxxx are
autofs-drop-dentry-reference-only-when-it-is-never-used.patch
