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 4752031281E; Thu, 27 Nov 2025 14:58:11 +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=1764255491; cv=none; b=UegW4emhab4lJ3hHxQJ+v9Cx0XK/FYWybkHRuOQXapenXTT5+Gh/vbpRi8lrsJl2qjzJvMgWFtXqrJ6nW0SF9ZIh5qp2ewjYZCd26YqzbcW9wYDa2j7SEzV40mZlNBP7wZ2Nd++GbT/VMGygWcBu47adrpkbyxedDe70LPODox0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764255491; c=relaxed/simple; bh=WbhV3g1jeySNrupsXZVicaRROI61tShc+2XdiJqDVA8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rFc20MVv7Gyka/IF5t/EtvxxFlz+lQzp9mJsBxi6dCDGAb97GT34BEa5yuOibg7pk74PzhWp3VOxhD5LM9RkwdVtzvBk2x5J7e+/V/O7p5gazy6GErXKW0i6KE4khmPNCbiDj++NQp7AlBfbxOSso6y8HnmaoZxhTUuXEgS60KU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NCEGFQuH; 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="NCEGFQuH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5EB2C4CEF8; Thu, 27 Nov 2025 14:58:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764255491; bh=WbhV3g1jeySNrupsXZVicaRROI61tShc+2XdiJqDVA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NCEGFQuH2kg5luY6zMxkv5vkwGtv7ZhJLqV074EbfIyRmJl/GtmJUGTRwtS+JNVba 5jR6gSaAmzEa8a0RhgJf+9NYaxL6KluT0EMaAkqn6cxJKJhL5z4T//PysBvL6e6xpw SlkNrvHsHuJtirU0F806gHMQXqlnzkPJOD9684V8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matthew Wilcox , "Darrick J. Wong" , Jan Kara , OGAWA Hirofumi , Christoph Hellwig , Yongpeng Yang , Christian Brauner Subject: [PATCH 6.17 012/175] vfat: fix missing sb_min_blocksize() return value checks Date: Thu, 27 Nov 2025 15:44:25 +0100 Message-ID: <20251127144043.405058560@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251127144042.945669935@linuxfoundation.org> References: <20251127144042.945669935@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yongpeng Yang commit 63b5aa01da0f38cdbd97d021477258e511631497 upstream. When emulating an nvme device on qemu with both logical_block_size and physical_block_size set to 8 KiB, but without format, a kernel panic was triggered during the early boot stage while attempting to mount a vfat filesystem. [95553.682035] EXT4-fs (nvme0n1): unable to set blocksize [95553.684326] EXT4-fs (nvme0n1): unable to set blocksize [95553.686501] EXT4-fs (nvme0n1): unable to set blocksize [95553.696448] ISOFS: unsupported/invalid hardware sector size 8192 [95553.697117] ------------[ cut here ]------------ [95553.697567] kernel BUG at fs/buffer.c:1582! [95553.697984] Oops: invalid opcode: 0000 [#1] SMP NOPTI [95553.698602] CPU: 0 UID: 0 PID: 7212 Comm: mount Kdump: loaded Not tainted 6.18.0-rc2+ #38 PREEMPT(voluntary) [95553.699511] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [95553.700534] RIP: 0010:folio_alloc_buffers+0x1bb/0x1c0 [95553.701018] Code: 48 8b 15 e8 93 18 02 65 48 89 35 e0 93 18 02 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc <0f> 0b 90 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f [95553.702648] RSP: 0018:ffffd1b0c676f990 EFLAGS: 00010246 [95553.703132] RAX: ffff8cfc4176d820 RBX: 0000000000508c48 RCX: 0000000000000001 [95553.703805] RDX: 0000000000002000 RSI: 0000000000000000 RDI: 0000000000000000 [95553.704481] RBP: ffffd1b0c676f9c8 R08: 0000000000000000 R09: 0000000000000000 [95553.705148] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [95553.705816] R13: 0000000000002000 R14: fffff8bc8257e800 R15: 0000000000000000 [95553.706483] FS: 000072ee77315840(0000) GS:ffff8cfdd2c8d000(0000) knlGS:0000000000000000 [95553.707248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [95553.707782] CR2: 00007d8f2a9e5a20 CR3: 0000000039d0c006 CR4: 0000000000772ef0 [95553.708439] PKRU: 55555554 [95553.708734] Call Trace: [95553.709015] [95553.709266] __getblk_slow+0xd2/0x230 [95553.709641] ? find_get_block_common+0x8b/0x530 [95553.710084] bdev_getblk+0x77/0xa0 [95553.710449] __bread_gfp+0x22/0x140 [95553.710810] fat_fill_super+0x23a/0xfc0 [95553.711216] ? __pfx_setup+0x10/0x10 [95553.711580] ? __pfx_vfat_fill_super+0x10/0x10 [95553.712014] vfat_fill_super+0x15/0x30 [95553.712401] get_tree_bdev_flags+0x141/0x1e0 [95553.712817] get_tree_bdev+0x10/0x20 [95553.713177] vfat_get_tree+0x15/0x20 [95553.713550] vfs_get_tree+0x2a/0x100 [95553.713910] vfs_cmd_create+0x62/0xf0 [95553.714273] __do_sys_fsconfig+0x4e7/0x660 [95553.714669] __x64_sys_fsconfig+0x20/0x40 [95553.715062] x64_sys_call+0x21ee/0x26a0 [95553.715453] do_syscall_64+0x80/0x670 [95553.715816] ? __fs_parse+0x65/0x1e0 [95553.716172] ? fat_parse_param+0x103/0x4b0 [95553.716587] ? vfs_parse_fs_param_source+0x21/0xa0 [95553.717034] ? __do_sys_fsconfig+0x3d9/0x660 [95553.717548] ? __x64_sys_fsconfig+0x20/0x40 [95553.717957] ? x64_sys_call+0x21ee/0x26a0 [95553.718360] ? do_syscall_64+0xb8/0x670 [95553.718734] ? __x64_sys_fsconfig+0x20/0x40 [95553.719141] ? x64_sys_call+0x21ee/0x26a0 [95553.719545] ? do_syscall_64+0xb8/0x670 [95553.719922] ? x64_sys_call+0x1405/0x26a0 [95553.720317] ? do_syscall_64+0xb8/0x670 [95553.720702] ? __x64_sys_close+0x3e/0x90 [95553.721080] ? x64_sys_call+0x1b5e/0x26a0 [95553.721478] ? do_syscall_64+0xb8/0x670 [95553.721841] ? irqentry_exit+0x43/0x50 [95553.722211] ? exc_page_fault+0x90/0x1b0 [95553.722681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [95553.723166] RIP: 0033:0x72ee774f3afe [95553.723562] Code: 73 01 c3 48 8b 0d 0a 33 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 49 89 ca b8 af 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d da 32 0f 00 f7 d8 64 89 01 48 [95553.725188] RSP: 002b:00007ffe97148978 EFLAGS: 00000246 ORIG_RAX: 00000000000001af [95553.725892] RAX: ffffffffffffffda RBX: 00005dcfe53d0080 RCX: 000072ee774f3afe [95553.726526] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 [95553.727176] RBP: 00007ffe97148ac0 R08: 0000000000000000 R09: 000072ee775e7ac0 [95553.727818] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [95553.728459] R13: 00005dcfe53d04b0 R14: 000072ee77670b00 R15: 00005dcfe53d1a28 [95553.729086] The panic occurs as follows: 1. logical_block_size is 8KiB, causing {struct super_block *sb}->s_blocksize is initialized to 0. vfat_fill_super - fat_fill_super - sb_min_blocksize - sb_set_blocksize //return 0 when size is 8KiB. 2. __bread_gfp is called with size == 0, causing folio_alloc_buffers() to compute an offset equal to folio_size(folio), which triggers a BUG_ON. fat_fill_super - sb_bread - __bread_gfp // size == {struct super_block *sb}->s_blocksize == 0 - bdev_getblk - __getblk_slow - grow_buffers - grow_dev_folio - folio_alloc_buffers // size == 0 - folio_set_bh //offset == folio_size(folio) and panic To fix this issue, add proper return value checks for sb_min_blocksize(). Cc: stable@vger.kernel.org # v6.15 Fixes: a64e5a596067bd ("bdev: add back PAGE_SIZE block size validation for sb_set_blocksize()") Reviewed-by: Matthew Wilcox Reviewed-by: Darrick J. Wong Reviewed-by: Jan Kara Reviewed-by: OGAWA Hirofumi Reviewed-by: Christoph Hellwig Signed-off-by: Yongpeng Yang Link: https://patch.msgid.link/20251104125009.2111925-2-yangyongpeng.storage@gmail.com Acked-by: OGAWA Hirofumi Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/fat/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 9648ed097816..9cfe20a3daaf 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1595,8 +1595,12 @@ int fat_fill_super(struct super_block *sb, struct fs_context *fc, setup(sb); /* flavour-specific stuff that needs options */ + error = -EINVAL; + if (!sb_min_blocksize(sb, 512)) { + fat_msg(sb, KERN_ERR, "unable to set blocksize"); + goto out_fail; + } error = -EIO; - sb_min_blocksize(sb, 512); bh = sb_bread(sb, 0); if (bh == NULL) { fat_msg(sb, KERN_ERR, "unable to read boot sector"); -- 2.52.0