2010-01-11 18:37:49

by OGAWA Hirofumi

Subject: [PATCH] ocfs2: Fix refcnt leak on ocfs2_fast_follow_link() error path

If ->follow_link handler return the error, it should decrement
nd->path refcnt. But, ocfs2_fast_follow_link() doesn't decrement.

This patch fix it by using usual nd_set_link() style error handling,
instead of playing with nd->path.

Signed-off-by: OGAWA Hirofumi <[email protected]>
---

fs/ocfs2/symlink.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff -puN fs/ocfs2/symlink.c~namei-ocfs2-follow_link-fix fs/ocfs2/symlink.c
--- linux-2.6/fs/ocfs2/symlink.c~namei-ocfs2-follow_link-fix 2010-01-12 00:15:14.000000000 +0900
+++ linux-2.6-hirofumi/fs/ocfs2/symlink.c 2010-01-12 00:15:14.000000000 +0900
@@ -137,20 +137,20 @@ static void *ocfs2_fast_follow_link(stru
}

memcpy(link, target, len);
- nd_set_link(nd, link);

bail:
+ nd_set_link(nd, status ? ERR_PTR(status) : link);
brelse(bh);

mlog_exit(status);
- return status ? ERR_PTR(status) : link;
+ return NULL;
}

static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
{
- char *link = cookie;
-
- kfree(link);
+ char *link = nd_get_link(nd);
+ if (!IS_ERR(link))
+ kfree(link);
}

const struct inode_operations ocfs2_symlink_inode_operations = {
_

--
OGAWA Hirofumi <[email protected]>

2010-01-12 00:39:44

by Joel Becker

Subject: Re: [PATCH] ocfs2: Fix refcnt leak on ocfs2_fast_follow_link() error path

On Tue, Jan 12, 2010 at 03:37:45AM +0900, OGAWA Hirofumi wrote:
>
> If ->follow_link handler return the error, it should decrement
> nd->path refcnt. But, ocfs2_fast_follow_link() doesn't decrement.
>
> This patch fix it by using usual nd_set_link() style error handling,
> instead of playing with nd->path.
>
> Signed-off-by: OGAWA Hirofumi <[email protected]>

This patch is now in the fixes branch of ocfs2.git.

Joel

--

"Against stupidity the Gods themselves contend in vain."
- Friedrich von Schiller

Joel Becker
Principal Software Developer
Oracle
E-mail: [email protected]
Phone: (650) 506-8127