From: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> [ Upstream commit 3b185255bb2f34fa6927619b9ef27f192a3d9f5a ] Following process triggers a memleak caused by forgetting to release the initial next anchor PEB (CONFIG_MTD_UBI_FASTMAP is disabled): 1. attach -> __erase_worker -> produce the initial next anchor PEB 2. detach -> ubi_fastmap_close (Do nothing, it should have released the initial next anchor PEB) Don't produce the initial next anchor PEB in __erase_worker() when fastmap is disabled. Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> Suggested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> Fixes: f9c34bb529975fe ("ubi: Fix producing anchor PEBs") Reported-by: syzbot+d9aab50b1154e3d163f5@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/mtd/ubi/wl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 27636063ed1bb..42cac572f82dc 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -1086,7 +1086,8 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk) if (!err) { spin_lock(&ubi->wl_lock); - if (!ubi->fm_next_anchor && e->pnum < UBI_FM_MAX_START) { + if (!ubi->fm_disabled && !ubi->fm_next_anchor && + e->pnum < UBI_FM_MAX_START) { /* Abort anchor production, if needed it will be * enabled again in the wear leveling started below. */ -- 2.25.1