commit: 46e4690bbd9a4f8d9e7c4f34e34b48f703ad47e0 From: Tao Ma <[email protected]> Date: Mon, 4 Apr 2011 16:00:49 -0400 Subject: [PATCH] ext4: fix a double free in ext4_register_li_request
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 <[email protected]> Reviewed-by: Lukas Czerner <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Cc: [email protected] --- fs/ext4/super.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 35ff9fe..35bd020 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2975,6 +2975,12 @@ static int ext4_register_li_request(struct super_block *sb, mutex_unlock(&ext4_li_info->li_list_mtx); 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(); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
