linux-kernel - [PATCH 5.6 052/166] f2fs: fix to avoid use-after-free in f2fs_write_multi

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]

Message-Id: <20200422095054.595424518@linuxfoundation.org>
Date:   Wed, 22 Apr 2020 11:56:19 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Chao Yu <yuchao0@...wei.com>,
        Jaegeuk Kim <jaegeuk@...nel.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.6 052/166] f2fs: fix to avoid use-after-free in f2fs_write_multi_pages()

From: Chao Yu <yuchao0@...wei.com>

[ Upstream commit 95978caa138948054e06d00bfc3432b518699f1b ]

In compress cluster, if physical block number is less than logic
page number, race condition will cause use-after-free issue as
described below:

- f2fs_write_compressed_pages
 - fio.page = cic->rpages[0];
 - f2fs_outplace_write_data
					- f2fs_compress_write_end_io
					 - kfree(cic->rpages);
					 - kfree(cic);
 - fio.page = cic->rpages[1];

f2fs_write_multi_pages+0xfd0/0x1a98
f2fs_write_data_pages+0x74c/0xb5c
do_writepages+0x64/0x108
__writeback_single_inode+0xdc/0x4b8
writeback_sb_inodes+0x4d0/0xa68
__writeback_inodes_wb+0x88/0x178
wb_writeback+0x1f0/0x424
wb_workfn+0x2f4/0x574
process_one_work+0x210/0x48c
worker_thread+0x2e8/0x44c
kthread+0x110/0x120
ret_from_fork+0x10/0x18

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@...wei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/f2fs/compress.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index c847523ab4a2e..927db1205bd81 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -845,7 +845,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 
 		blkaddr = datablock_addr(dn.inode, dn.node_page,
 							dn.ofs_in_node);
-		fio.page = cic->rpages[i];
+		fio.page = cc->rpages[i];
 		fio.old_blkaddr = blkaddr;
 
 		/* cluster header */
-- 
2.20.1