Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Dongliang Mu <dzm91@hust.edu.cn>
To:     Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <chao@kernel.org>
Cc:     Dongliang Mu <mudongliangabcd@gmail.com>,
        syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Date:   Fri, 15 Apr 2022 21:19:02 +0800
Message-Id: <20220415131902.55028-1-dzm91@hust.edu.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Dongliang Mu <mudongliangabcd@gmail.com>

Syzbot triggers two WARNs in f2fs_is_valid_blkaddr and
__is_bitmap_valid. For example, in f2fs_is_valid_blkaddr,
if type is DATA_GENERIC_ENHANCE or DATA_GENERIC_ENHANCE_READ,
it invokes WARN_ON if blkaddr is not in the right range.
The call trace is as follows:

 f2fs_get_node_info+0x45f/0x1070
 read_node_page+0x577/0x1190
 __get_node_page.part.0+0x9e/0x10e0
 __get_node_page
 f2fs_get_node_page+0x109/0x180
 do_read_inode
 f2fs_iget+0x2a5/0x58b0
 f2fs_fill_super+0x3b39/0x7ca0

Fix these two WARNs by replacing WARN_ON with dump_stack.

Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
v1->v2: as suggested by Chao Yu, change WARN_ON to dump_stack
 fs/f2fs/checkpoint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index f5366feea82d..4dfae0cc6b16 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -158,7 +158,7 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
 		f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
 			 blkaddr, exist);
 		set_sbi_flag(sbi, SBI_NEED_FSCK);
-		WARN_ON(1);
+		dump_stack();
 	}
 	return exist;
 }
@@ -196,7 +196,7 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
 			f2fs_warn(sbi, "access invalid blkaddr:%u",
 				  blkaddr);
 			set_sbi_flag(sbi, SBI_NEED_FSCK);
-			WARN_ON(1);
+			dump_stack();
 			return false;
 		} else {
 			return __is_bitmap_valid(sbi, blkaddr, type);
-- 
2.25.1