Commit bdcb8aa4 authored by Juntong Deng's avatar Juntong Deng Committed by Andreas Gruenbacher
Browse files

gfs2: Fix slab-use-after-free in gfs2_qd_dealloc 



In gfs2_put_super(), whether withdrawn or not, the quota should
be cleaned up by gfs2_quota_cleanup().

Otherwise, struct gfs2_sbd will be freed before gfs2_qd_dealloc (rcu
callback) has run for all gfs2_quota_data objects, resulting in
use-after-free.

Also, gfs2_destroy_threads() and gfs2_quota_cleanup() is already called
by gfs2_make_fs_ro(), so in gfs2_put_super(), after calling
gfs2_make_fs_ro(), there is no need to call them again.

Reported-by: default avatar <syzbot+29c47e9e51895928698c@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=29c47e9e51895928698c


Signed-off-by: default avatarJuntong Deng <juntong.deng@outlook.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent 074d7306

fs/gfs2/super.c

+6 −4
Original line number Diff line number Diff line
@@ -602,13 +602,15 @@ static void gfs2_put_super(struct super_block *sb) 
	}

	spin_unlock(&sdp->sd_jindex_spin);



	if (!sb_rdonly(sb)) {

	if (!sb_rdonly(sb))

		gfs2_make_fs_ro(sdp);

	}

	if (gfs2_withdrawn(sdp)) {

	else {

		if (gfs2_withdrawn(sdp))

			gfs2_destroy_threads(sdp);



		gfs2_quota_cleanup(sdp);

	}



	WARN_ON(gfs2_withdrawing(sdp));



	/*  At this point, we're through modifying the disk  */