9p: fix a potential acl leak

posix_acl_update_mode() could possibly clear 'acl', if so we leak the
memory pointed by 'acl'.  Save this pointer before calling
posix_acl_update_mode() and release the memory if 'acl' really gets
cleared.

Link: http://lkml.kernel.org/r/1486678332-2430-1-git-send-email-xiyou.wangcong@gmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reported-by: Mark Salyzyn <salyzyn@android.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Cong Wang 2017-02-22 15:40:53 -08:00 committed by Linus Torvalds
parent 612dafabb6
commit b5c66bab72
1 changed files with 2 additions and 0 deletions

View File

@ -277,6 +277,7 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
case ACL_TYPE_ACCESS: case ACL_TYPE_ACCESS:
if (acl) { if (acl) {
struct iattr iattr; struct iattr iattr;
struct posix_acl *old_acl = acl;
retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl); retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
if (retval) if (retval)
@ -287,6 +288,7 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
* by the mode bits. So don't * by the mode bits. So don't
* update ACL. * update ACL.
*/ */
posix_acl_release(old_acl);
value = NULL; value = NULL;
size = 0; size = 0;
} }