linux-kernel - [PATCH AUTOSEL 5.4 323/330] ubi: fastmap: Free unused fastmap anchor peb during detach

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 17 Sep 2020 22:01:03 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Hou Tao <houtao1@...wei.com>,
        syzbot+f317896aae32eb281a58@...kaller.appspotmail.com,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Richard Weinberger <richard@....at>,
        Sasha Levin <sashal@...nel.org>, linux-mtd@...ts.infradead.org
Subject: [PATCH AUTOSEL 5.4 323/330] ubi: fastmap: Free unused fastmap anchor peb during detach

From: Hou Tao <houtao1@...wei.com>

[ 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@...kaller.appspotmail.com
Reviewed-by: Sascha Hauer <s.hauer@...gutronix.de>
Signed-off-by: Hou Tao <houtao1@...wei.com>
Signed-off-by: Richard Weinberger <richard@....at>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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