From: Andreas Gruenbacher Date: Sun, 14 Dec 2025 16:47:34 +0000 (+0000) Subject: gfs2: Fix slab-use-after-free in qd_put X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=22150a7d401d9e9169b9b68e05bed95f7f49bf69;p=thirdparty%2Flinux.git gfs2: Fix slab-use-after-free in qd_put Commit a475c5dd16e5 ("gfs2: Free quota data objects synchronously") started freeing quota data objects during filesystem shutdown instead of putting them back onto the LRU list, but it failed to remove these objects from the LRU list, causing LRU list corruption. This caused use-after-free when the shrinker (gfs2_qd_shrink_scan) tried to access already-freed objects on the LRU list. Fix this by removing qd objects from the LRU list before freeing them in qd_put(). Initial fix from Deepanshu Kartikey . Fixes: a475c5dd16e5 ("gfs2: Free quota data objects synchronously") Reported-by: syzbot+046b605f01802054bff0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=046b605f01802054bff0 Signed-off-by: Andreas Gruenbacher --- diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 21dfe1e48da6e..1c3455093ae8c 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -334,6 +334,7 @@ static void qd_put(struct gfs2_quota_data *qd) lockref_mark_dead(&qd->qd_lockref); spin_unlock(&qd->qd_lockref.lock); + list_lru_del_obj(&gfs2_qd_lru, &qd->qd_lru); gfs2_qd_dispose(qd); return; }