From: Hou Tao <houtao1@xxxxxxxxxx> [ Upstream commit c16f39d14a7e0ec59881fbdb22ae494907534384 ] When CONFIG_MTD_UBI_FASTMAP is enabled, fm_anchor will be assigned a free PEB during ubi_wl_init() or ubi_update_fastmap(). However if fastmap is not used or disabled on the MTD device, ubi_wl_entry related with the PEB will not be freed during detach. So Fix it by freeing the unused fastmap anchor during detach. Fixes: f9c34bb52997 ("ubi: Fix producing anchor PEBs") Reported-by: syzbot+f317896aae32eb281a58@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> Signed-off-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/mtd/ubi/fastmap-wl.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c index 426820ab9afe1..b486250923c5a 100644 --- a/drivers/mtd/ubi/fastmap-wl.c +++ b/drivers/mtd/ubi/fastmap-wl.c @@ -39,6 +39,13 @@ static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root) return victim; } +static inline void return_unused_peb(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + wl_tree_add(e, &ubi->free); + ubi->free_count++; +} + /** * return_unused_pool_pebs - returns unused PEB to the free tree. * @ubi: UBI device description object @@ -52,8 +59,7 @@ static void return_unused_pool_pebs(struct ubi_device *ubi, for (i = pool->used; i < pool->size; i++) { e = ubi->lookuptbl[pool->pebs[i]]; - wl_tree_add(e, &ubi->free); - ubi->free_count++; + return_unused_peb(ubi, e); } } @@ -361,6 +367,11 @@ static void ubi_fastmap_close(struct ubi_device *ubi) return_unused_pool_pebs(ubi, &ubi->fm_pool); return_unused_pool_pebs(ubi, &ubi->fm_wl_pool); + if (ubi->fm_anchor) { + return_unused_peb(ubi, ubi->fm_anchor); + ubi->fm_anchor = NULL; + } + if (ubi->fm) { for (i = 0; i < ubi->fm->used_blocks; i++) kfree(ubi->fm->e[i]); -- 2.25.1