path: root/fs
diff options
authorTao Ma <boyu.mt@taobao.com>2011-04-04 16:00:49 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-04-14 13:02:40 -0700
commit53224a1f02f493bb1a37bad94b596cc4314777e6 (patch)
treefa783e68aaa7146a0b302373fdb0944a8b2f51d4 /fs
parenta691a7c96629740253fc52c30460607b98e05328 (diff)
ext4: fix a double free in ext4_register_li_request
commit 46e4690bbd9a4f8d9e7c4f34e34b48f703ad47e0 upstream. In ext4_register_li_request, we malloc a ext4_li_request and inserts it into ext4_li_info->li_request_list. In case of any error later, we free it in the end. But if we have some error in ext4_run_lazyinit_thread, the whole li_request_list will be dropped and freed in it. So we will double free this ext4_li_request. This patch just sets elr to NULL after it is inserted to the list so that the latter kfree won't double free it. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4381efee3db..243deb021e7 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2978,6 +2978,12 @@ static int ext4_register_li_request(struct super_block *sb,
sbi->s_li_request = elr;
+ /*
+ * set elr to NULL here since it has been inserted to
+ * the request_list and the removal and free of it is
+ * handled by ext4_clear_request_list from now on.
+ */
+ elr = NULL;
if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
ret = ext4_run_lazyinit_thread();