From: Hou Tao <houtao1@xxxxxxxxxx>
commit c16f39d14a7e0ec59881fbdb22ae494907534384 upstream.
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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/ubi/fastmap-wl.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--- 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_
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(stru
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
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]);
