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 5D7B235505C; Tue, 6 Jan 2026 17:25:38 +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=1767720338; cv=none; b=GWcNLQxlnTp5lpnqqy8fjGPOnXN0FZnQKFUu+PErv4l+Y6uJXgH2skPCS3sarKcHZ57Y/ZYbUeTW/MLBcmdlk049dVOk72VmN7lHRtIO5I3CspXVaTpJxHt310QTw4xKN0B3LEbimrzwoAUfe3WAGLSF6XkFtoWNsAZ2lO3oQoE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767720338; c=relaxed/simple; bh=htQDHs2n12lxUWS1iSgK3KNjcKoLXDxQJcBJyuptkzo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=faCQNoV/2DM9ZKe3ngZNHMZx4J8zz2P4/JlvmuACxgkE6teA+eTj15NIDM00vADnIimosU1TJMpEwmosJ3yUXMY4H1tjT//P4QaHfvbOFokruDe68BOqedJFjoq8xhK5lCp5H7Mfe9Qsl0pP2fHuuOQ2LkzNeEa21tyunVLVwfE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lEW7PA67; 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="lEW7PA67" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE28DC116C6; Tue, 6 Jan 2026 17:25:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767720338; bh=htQDHs2n12lxUWS1iSgK3KNjcKoLXDxQJcBJyuptkzo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lEW7PA67FdENSVB+3y7nRMCeM8ZbTixRM1x3HFctCN7v3v23KOnvyf7IXqsVTU3rI TOOeG/Uqwn5S+hy7WHfAav9p+iSv+N/a99xKBAdZR0hCiER2PLsZpd2YKx+r2BV7p1 cA3qynMFUgwP+0bC8GL1pR5xVGQgs1bT2rWFDv5k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, syzbot+24124df3170c3638b35f@syzkaller.appspotmail.com, Chao Yu , Jaegeuk Kim Subject: [PATCH 6.12 205/567] f2fs: fix to avoid updating zero-sized extent in extent cache Date: Tue, 6 Jan 2026 17:59:47 +0100 Message-ID: <20260106170458.907041844@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260106170451.332875001@linuxfoundation.org> References: <20260106170451.332875001@linuxfoundation.org> User-Agent: quilt/0.69 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 7c37c79510329cd951a4dedf3f7bf7e2b18dccec upstream. As syzbot reported: F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0] ------------[ cut here ]------------ kernel BUG at fs/f2fs/extent_cache.c:678! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678 Call Trace: f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline] f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030 vfs_fallocate+0x669/0x7e0 fs/open.c:342 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x611/0x780 fs/ioctl.c:-1 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bc58eec9 In error path of f2fs_zero_range(), it may add a zero-sized extent into extent cache, it should be avoided. Fixes: 6e9619499f53 ("f2fs: support in batch fzero in dnode page") Cc: stable@kernel.org Reported-by: syzbot+24124df3170c3638b35f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/68e5d698.050a0220.256323.0032.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1594,8 +1594,11 @@ static int f2fs_do_zero_range(struct dno f2fs_set_data_blkaddr(dn, NEW_ADDR); } - f2fs_update_read_extent_cache_range(dn, start, 0, index - start); - f2fs_update_age_extent_cache_range(dn, start, index - start); + if (index > start) { + f2fs_update_read_extent_cache_range(dn, start, 0, + index - start); + f2fs_update_age_extent_cache_range(dn, start, index - start); + } return ret; }