[PATCH v3 0/2] ubi: fastmap: Produce and release fm_anchor peb correctly

[PATCH v3 0/2] ubi: fastmap: Produce and release fm_anchor peb correctly

[Zhihao Cheng]

v1 -> v2:
  Adapt Sascha's suggestions for fm_diabled checking in __erase_worker().
v2 -> v3:
  Free fm_anchor peb during cloing fastmap.

Zhihao Cheng (2):
  ubi: fastmap: Don't produce the initial next anchor PEB when fastmap
    is disabled
  ubi: fastmap: Free fastmap next anchor peb during detach

 drivers/mtd/ubi/fastmap-wl.c | 5 +++++
 drivers/mtd/ubi/wl.c         | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

-- 
2.25.4


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[PATCH v3 1/2] ubi: fastmap: Don't produce the initial next anchor PEB when fastmap is disabled

[Zhihao Cheng]

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@huawei.com>
Suggested-by: Sascha Hauer <s.hauer@pengutronix.de>
Fixes: f9c34bb529975fe ("ubi: Fix producing anchor PEBs")
Reported-by: syzbot+d9aab50b1154e3d163f5@syzkaller.appspotmail.com
---
 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 27636063ed1b..42cac572f82d 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.
 			 */
-- 
2.25.4


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[PATCH v3 2/2] ubi: fastmap: Free fastmap next anchor peb during detach

[Zhihao Cheng]

ubi_wl_entry related with the fm_next_anchor PEB is not freed during
detach, which causes a memory leak.
Don't forget to release fm_next_anchor PEB while detaching ubi from
mtd when CONFIG_MTD_UBI_FASTMAP is enabled.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Fixes: 4b68bf9a69d22d ("ubi: Select fastmap anchor PEBs considering...")
---
 drivers/mtd/ubi/fastmap-wl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c
index 83afc00e365a..28f55f9cf715 100644
--- a/drivers/mtd/ubi/fastmap-wl.c
+++ b/drivers/mtd/ubi/fastmap-wl.c
@@ -381,6 +381,11 @@ static void ubi_fastmap_close(struct ubi_device *ubi)
 		ubi->fm_anchor = NULL;
 	}
 
+	if (ubi->fm_next_anchor) {
+		return_unused_peb(ubi, ubi->fm_next_anchor);
+		ubi->fm_next_anchor = NULL;
+	}
+
 	if (ubi->fm) {
 		for (i = 0; i < ubi->fm->used_blocks; i++)
 			kfree(ubi->fm->e[i]);
-- 
2.25.4


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