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From: Chao Yu <chao@kernel.org>
To: jaegeuk@kernel.org
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	Ming Yan <yanming@tju.edu.cn>
Subject: [f2fs-dev] [PATCH] f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count()
Date: Wed, 27 Apr 2022 01:06:02 +0800	[thread overview]
Message-ID: <20220426170602.7431-1-chao@kernel.org> (raw)

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215897

I have encountered a bug in F2FS file system in kernel v5.17.

The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
reproduce the bug by running the following commands:

The kernel message is shown below:

kernel BUG at fs/f2fs/f2fs.h:2511!
Call Trace:
 f2fs_remove_inode_page+0x2a2/0x830
 f2fs_evict_inode+0x9b7/0x1510
 evict+0x282/0x4e0
 do_unlinkat+0x33a/0x540
 __x64_sys_unlinkat+0x8e/0xd0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is: .total_valid_block_count or .total_valid_node_count
could fuzzed to zero, then once dec_valid_node_count() was called, it
will cause BUG_ON(), this patch fixes to print warning info and set
SBI_NEED_FSCK into CP instead of panic.

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
---
 fs/f2fs/f2fs.h | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f3eda4f13646..56adc3b68e14 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2605,11 +2605,17 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
 {
 	spin_lock(&sbi->stat_lock);
 
-	f2fs_bug_on(sbi, !sbi->total_valid_block_count);
-	f2fs_bug_on(sbi, !sbi->total_valid_node_count);
+	if (unlikely(!sbi->total_valid_block_count ||
+			!sbi->total_valid_node_count)) {
+		f2fs_warn(sbi, "dec_valid_node_count: inconsistent block counts, total_valid_block:%u, total_valid_node:%u",
+			  sbi->total_valid_block_count,
+			  sbi->total_valid_node_count);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+	} else {
+		sbi->total_valid_block_count--;
+		sbi->total_valid_node_count--;
+	}
 
-	sbi->total_valid_node_count--;
-	sbi->total_valid_block_count--;
 	if (sbi->reserved_blocks &&
 		sbi->current_reserved_blocks < sbi->reserved_blocks)
 		sbi->current_reserved_blocks++;
-- 
2.32.0



_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

WARNING: multiple messages have this Message-ID (diff)
From: Chao Yu <chao@kernel.org>
To: jaegeuk@kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org, Chao Yu <chao@kernel.org>,
	stable@vger.kernel.org, Ming Yan <yanming@tju.edu.cn>,
	Chao Yu <chao.yu@oppo.com>
Subject: [PATCH] f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count()
Date: Wed, 27 Apr 2022 01:06:02 +0800	[thread overview]
Message-ID: <20220426170602.7431-1-chao@kernel.org> (raw)

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215897

I have encountered a bug in F2FS file system in kernel v5.17.

The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
reproduce the bug by running the following commands:

The kernel message is shown below:

kernel BUG at fs/f2fs/f2fs.h:2511!
Call Trace:
 f2fs_remove_inode_page+0x2a2/0x830
 f2fs_evict_inode+0x9b7/0x1510
 evict+0x282/0x4e0
 do_unlinkat+0x33a/0x540
 __x64_sys_unlinkat+0x8e/0xd0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is: .total_valid_block_count or .total_valid_node_count
could fuzzed to zero, then once dec_valid_node_count() was called, it
will cause BUG_ON(), this patch fixes to print warning info and set
SBI_NEED_FSCK into CP instead of panic.

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
---
 fs/f2fs/f2fs.h | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f3eda4f13646..56adc3b68e14 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2605,11 +2605,17 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
 {
 	spin_lock(&sbi->stat_lock);
 
-	f2fs_bug_on(sbi, !sbi->total_valid_block_count);
-	f2fs_bug_on(sbi, !sbi->total_valid_node_count);
+	if (unlikely(!sbi->total_valid_block_count ||
+			!sbi->total_valid_node_count)) {
+		f2fs_warn(sbi, "dec_valid_node_count: inconsistent block counts, total_valid_block:%u, total_valid_node:%u",
+			  sbi->total_valid_block_count,
+			  sbi->total_valid_node_count);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+	} else {
+		sbi->total_valid_block_count--;
+		sbi->total_valid_node_count--;
+	}
 
-	sbi->total_valid_node_count--;
-	sbi->total_valid_block_count--;
 	if (sbi->reserved_blocks &&
 		sbi->current_reserved_blocks < sbi->reserved_blocks)
 		sbi->current_reserved_blocks++;
-- 
2.32.0


             reply	other threads:[~2022-04-27 12:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-26 17:06 Chao Yu [this message]
2022-04-26 17:06 ` [PATCH] f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count() Chao Yu

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