From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EB4A280A29 for ; Tue, 17 Feb 2026 15:20:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771341636; cv=none; b=CNi2pJ3UBVwPBXA3Qaixni4mhr7G5qF1clAleJSkxhdqvGJAlyui7F8ZSlitNSrq6dYmPY2e/6v448zf8mXrlhGBPK5SazYKWHdDgNDuTdC7gRgrRPfbCr27Kcnjz9Hnt/NwvtoRJDWb1JsYN8lBks+tA5DL4nPYknOrvkWDd0A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771341636; c=relaxed/simple; bh=DEg0TSX8yLRTvMvKucgXP1k7dBhbB9relrG0k/qhxZc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b5ruVtW0CC6WRniDjMTMgLCQuYJwhwYrWbEvnv47sr7eUY3P6zUKPz3MBl0KO8+y9N61tN4bVVE5ybNwCOza7oBT1XpR2glggNmvGSWjsW0zhq/lW7svfz8GkOUOe8tPO/t/bFjJ++wOqOi57PdXjD8LIz0MeU6Of+JYTZSz2bE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=q9gVJf9O; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="q9gVJf9O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69C6DC19424; Tue, 17 Feb 2026 15:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771341636; bh=DEg0TSX8yLRTvMvKucgXP1k7dBhbB9relrG0k/qhxZc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q9gVJf9OHC/Gu9RptAyYOKrgwdkMtpewMwyeABQD6a8+s3Sbhtk2g6WBAmmzbCT5M TCctYCYN+9VKNS95eL9OrCazzn2GlsD8Orp+6tbogApoZddT7a+Lnqq1laODSnfVN3 ejzDQ6KJYpLJNntJZ7TUGbicV3NniWBDYtEA8kM3olVynsBxXXvPr5EtFjgFeey8/1 W8WvMuP9c8O2pLZNihdnHy3Ef4wR1vrahsXHlP++6zatmCbFMab4dIPmNT+d1RDS9Q 3eW7TuYohMj02tJcT+/QdDjkQV4Rxns5FWS9ABBYpsBIEdhWx8xVUU6zgMbY20aEMA tDlqkd7AgU4lA== From: Sasha Levin To: stable@vger.kernel.org Cc: Chao Yu , stable@kernel.org, Daeho Jeong , Xiaolong Guo , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.6.y 2/2] f2fs: fix to avoid mapping wrong physical block for swapfile Date: Tue, 17 Feb 2026 10:20:32 -0500 Message-ID: <20260217152032.3680679-2-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260217152032.3680679-1-sashal@kernel.org> References: <2026021700-wrongness-undermine-54e0@gregkh> <20260217152032.3680679-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chao Yu [ Upstream commit 5c145c03188bc9ba1c29e0bc4d527a5978fc47f9 ] Xiaolong Guo reported a f2fs bug in bugzilla [1] [1] https://bugzilla.kernel.org/show_bug.cgi?id=220951 Quoted: "When using stress-ng's swap stress test on F2FS filesystem with kernel 6.6+, the system experiences data corruption leading to either: 1 dm-verity corruption errors and device reboot 2 F2FS node corruption errors and boot hangs The issue occurs specifically when: 1 Using F2FS filesystem (ext4 is unaffected) 2 Swapfile size is less than F2FS section size (2MB) 3 Swapfile has fragmented physical layout (multiple non-contiguous extents) 4 Kernel version is 6.6+ (6.1 is unaffected) The root cause is in check_swap_activate() function in fs/f2fs/data.c. When the first extent of a small swapfile (< 2MB) is not aligned to section boundaries, the function incorrectly treats it as the last extent, failing to map subsequent extents. This results in incorrect swap_extent creation where only the first extent is mapped, causing subsequent swap writes to overwrite wrong physical locations (other files' data). Steps to Reproduce 1 Setup a device with F2FS-formatted userdata partition 2 Compile stress-ng from https://github.com/ColinIanKing/stress-ng 3 Run swap stress test: (Android devices) adb shell "cd /data/stressng; ./stress-ng-64 --metrics-brief --timeout 60 --swap 0" Log: 1 Ftrace shows in kernel 6.6, only first extent is mapped during second f2fs_map_blocks call in check_swap_activate(): stress-ng-swap-8990: f2fs_map_blocks: ino=11002, file offset=0, start blkaddr=0x43143, len=0x1 (Only 4KB mapped, not the full swapfile) 2 in kernel 6.1, both extents are correctly mapped: stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=0, start blkaddr=0x13cd4, len=0x1 stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=1, start blkaddr=0x60c84b, len=0xff The problematic code is in check_swap_activate(): if ((pblock - SM_I(sbi)->main_blkaddr) % blks_per_sec || nr_pblocks % blks_per_sec || !f2fs_valid_pinned_area(sbi, pblock)) { bool last_extent = false; not_aligned++; nr_pblocks = roundup(nr_pblocks, blks_per_sec); if (cur_lblock + nr_pblocks > sis->max) nr_pblocks -= blks_per_sec; /* this extent is last one */ if (!nr_pblocks) { nr_pblocks = last_lblock - cur_lblock; last_extent = true; } ret = f2fs_migrate_blocks(inode, cur_lblock, nr_pblocks); if (ret) { if (ret == -ENOENT) ret = -EINVAL; goto out; } if (!last_extent) goto retry; } When the first extent is unaligned and roundup(nr_pblocks, blks_per_sec) exceeds sis->max, we subtract blks_per_sec resulting in nr_pblocks = 0. The code then incorrectly assumes this is the last extent, sets nr_pblocks = last_lblock - cur_lblock (entire swapfile), and performs migration. After migration, it doesn't retry mapping, so subsequent extents are never processed. " In order to fix this issue, we need to lookup block mapping info after we migrate all blocks in the tail of swapfile. Cc: stable@kernel.org Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices") Cc: Daeho Jeong Reported-and-tested-by: Xiaolong Guo Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220951 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ f2fs_is_sequential_zone_area() => !f2fs_valid_pinned_area() ] Signed-off-by: Sasha Levin --- fs/f2fs/data.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index c863e27fd846b..244f2b5a36222 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3934,6 +3934,7 @@ static int check_swap_activate(struct swap_info_struct *sis, while (cur_lblock < last_lblock && cur_lblock < sis->max) { struct f2fs_map_blocks map; + bool last_extent = false; retry: cond_resched(); @@ -3959,11 +3960,10 @@ static int check_swap_activate(struct swap_info_struct *sis, pblock = map.m_pblk; nr_pblocks = map.m_len; - if ((pblock - SM_I(sbi)->main_blkaddr) % blks_per_sec || - nr_pblocks % blks_per_sec || - !f2fs_valid_pinned_area(sbi, pblock)) { - bool last_extent = false; - + if (!last_extent && + ((pblock - SM_I(sbi)->main_blkaddr) % blks_per_sec || + nr_pblocks % blks_per_sec || + !f2fs_valid_pinned_area(sbi, pblock))) { not_aligned++; nr_pblocks = roundup(nr_pblocks, blks_per_sec); @@ -3984,8 +3984,8 @@ static int check_swap_activate(struct swap_info_struct *sis, goto out; } - if (!last_extent) - goto retry; + /* lookup block mapping info after block migration */ + goto retry; } if (cur_lblock + nr_pblocks >= sis->max) -- 2.51.0