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 6F610219E8F; Sat, 7 Jun 2025 10:09:18 +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=1749290958; cv=none; b=eatJRe4XPzxwlbAytlcLWCNdCGh1nEOMSOjT1mrDXHhhqENKRovd8c7p/qH4oFvqG6KX/P3l//PQobwAbg5g6F7dYv1+Oh6JF8dafb1YGji8So8rECWjOjxsFinluanu2MwDVxDq1j5aORBLzH6PVccLm86501eUwl2JgCGdduY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749290958; c=relaxed/simple; bh=fhxUVzWavN97dR9p4RJkkWbJhMhNqMrc4iZ+mb282wA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P+Jh6DW7yciGW4I6ErAGmSgSvMcbA8zRgzi/gg6I3e84OzQt6wtW3Eyn+fwLuAQA83nSQAv2636DnDagKw7FulbAsnknb7Q0KIr/wgzngPkdvQ7wovdT5CMdNYlZV87NKiJId9WzjE7A7usmJWlv+c1mX35Vs/AB4y2dS/dQdMs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=09xY60lF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="09xY60lF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD46CC4CEED; Sat, 7 Jun 2025 10:09:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1749290958; bh=fhxUVzWavN97dR9p4RJkkWbJhMhNqMrc4iZ+mb282wA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=09xY60lFgqr4P3PULo2JtQRY7bkF/6fwcPK7Ye0brU3XSSyuw51GyYk9CINOmi1+m 4nQDGQqF6VUp3f7/yY2H6PraaLFHGp1VO+CxoCbXUGNRUUFlIvn4hbhZvQ+h0Gyk9v 5PP3pIJQsMjx/GDysc8AHTzdaisEPNgxBl7IYrxM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+b6b347b7a4ea1b2e29b6@syzkaller.appspotmail.com, Chao Yu , Jaegeuk Kim , Alva Lan Subject: [PATCH 6.12 02/24] f2fs: fix to avoid accessing uninitialized curseg Date: Sat, 7 Jun 2025 12:07:33 +0200 Message-ID: <20250607100718.006192189@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250607100717.910797456@linuxfoundation.org> References: <20250607100717.910797456@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chao Yu commit 986c50f6bca109c6cf362b4e2babcb85aba958f6 upstream. syzbot reports a f2fs bug as below: F2FS-fs (loop3): Stopped filesystem due to reason: 7 kworker/u8:7: attempt to access beyond end of device BUG: unable to handle page fault for address: ffffed1604ea3dfa RIP: 0010:get_ckpt_valid_blocks fs/f2fs/segment.h:361 [inline] RIP: 0010:has_curseg_enough_space fs/f2fs/segment.h:570 [inline] RIP: 0010:__get_secs_required fs/f2fs/segment.h:620 [inline] RIP: 0010:has_not_enough_free_secs fs/f2fs/segment.h:633 [inline] RIP: 0010:has_enough_free_secs+0x575/0x1660 fs/f2fs/segment.h:649 f2fs_is_checkpoint_ready fs/f2fs/segment.h:671 [inline] f2fs_write_inode+0x425/0x540 fs/f2fs/inode.c:791 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Commit 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT") allows to trigger no free segment fault in allocator, then it will update curseg->segno to NULL_SEGNO, though, CP_ERROR_FLAG has been set, f2fs_write_inode() missed to check the flag, and access invalid curseg->segno directly in below call path, then resulting in panic: - f2fs_write_inode - f2fs_is_checkpoint_ready - has_enough_free_secs - has_not_enough_free_secs - __get_secs_required - has_curseg_enough_space - get_ckpt_valid_blocks : access invalid curseg->segno To avoid this issue, let's: - check CP_ERROR_FLAG flag in prior to f2fs_is_checkpoint_ready() in f2fs_write_inode(). - in has_curseg_enough_space(), save curseg->segno into a temp variable, and verify its validation before use. Fixes: 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT") Reported-by: syzbot+b6b347b7a4ea1b2e29b6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67973c2b.050a0220.11b1bb.0089.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Alva Lan Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/inode.c | 7 +++++++ fs/f2fs/segment.h | 9 ++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -777,6 +777,13 @@ int f2fs_write_inode(struct inode *inode !is_inode_flag_set(inode, FI_DIRTY_INODE)) return 0; + /* + * no need to update inode page, ultimately f2fs_evict_inode() will + * clear dirty status of inode. + */ + if (f2fs_cp_error(sbi)) + return -EIO; + if (!f2fs_is_checkpoint_ready(sbi)) { f2fs_mark_inode_dirty_sync(inode, true); return -ENOSPC; --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -562,13 +562,16 @@ static inline bool has_curseg_enough_spa unsigned int node_blocks, unsigned int data_blocks, unsigned int dent_blocks) { - unsigned int segno, left_blocks, blocks; int i; /* check current data/node sections in the worst case. */ for (i = CURSEG_HOT_DATA; i < NR_PERSISTENT_LOG; i++) { segno = CURSEG_I(sbi, i)->segno; + + if (unlikely(segno == NULL_SEGNO)) + return false; + left_blocks = CAP_BLKS_PER_SEC(sbi) - get_ckpt_valid_blocks(sbi, segno, true); @@ -579,6 +582,10 @@ static inline bool has_curseg_enough_spa /* check current data section for dentry blocks. */ segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno; + + if (unlikely(segno == NULL_SEGNO)) + return false; + left_blocks = CAP_BLKS_PER_SEC(sbi) - get_ckpt_valid_blocks(sbi, segno, true); if (dent_blocks > left_blocks)