[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20221205150050.47784-2-hsiangkao@linux.alibaba.com>
Date: Mon, 5 Dec 2022 23:00:50 +0800
From: Gao Xiang <hsiangkao@...ux.alibaba.com>
To: linux-erofs@...ts.ozlabs.org, Chao Yu <chao@...nel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
Gao Xiang <hsiangkao@...ux.alibaba.com>,
syzbot+2ae90e873e97f1faf6f2@...kaller.appspotmail.com
Subject: [PATCH 2/2] erofs: validate the extent length for uncompressed pclusters
syzkaller reported a KASAN use-after-free:
https://syzkaller.appspot.com/bug?extid=2ae90e873e97f1faf6f2
The referenced fuzzed image actually has two issues:
- m_pa == 0 as a non-inlined pcluster;
- The logical length is longer than its physical length.
The first issue has already been addressed. This patch addresses
the second issue by checking the extent length validity.
Reported-by: syzbot+2ae90e873e97f1faf6f2@...kaller.appspotmail.com
Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter")
Signed-off-by: Gao Xiang <hsiangkao@...ux.alibaba.com>
---
fs/erofs/zmap.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 98eff1259de4..0150570c33aa 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -698,6 +698,11 @@ static int z_erofs_do_map_blocks(struct inode *inode,
}
if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) {
+ if (map->m_llen > map->m_plen) {
+ DBG_BUGON(1);
+ err = -EFSCORRUPTED;
+ goto unmap_out;
+ }
if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
map->m_algorithmformat =
Z_EROFS_COMPRESSION_INTERLACED;
--
2.24.4
Powered by blists - more mailing lists