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 A6FE8131BCE; Sun, 26 May 2024 09:43:51 +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=1716716631; cv=none; b=iWh62DIqyqjvHVss/Dm7LmXnld+zfGMyDfnQJNRhevVFSlJwq+pOGyp0OUxH39/ihWhtvXNuDSaqs2q9BuDxkDHMl57xRIZmnDR0SS1lBi3C93dUKDwwsxBmcVQg5rrjerJT5UGz7gxEpICj+yO8EwWX4aXFCzOHujxD/ATjRrk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716716631; c=relaxed/simple; bh=4Hx/U7MiYIQ+eFnMWjsQEcNrONO+JzOpAm5p7GNLqT8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WX6YeutLHKmfp2/p2dzu7EDgROUSy/9aI5r1PZ9CUr8fbbLemVjOFmHXL+1vGJh+z0WK1qdomwIIoQ3AJEuJKKQ8/PbroAkZtH3AhobLNBNGvMn/+UkgvWDFOriPSCyN9Lkj6ZHJlp+77C6BDq2IRtteJ4m4ySLJKq+HqLU0NrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Mf6YDH/J; 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="Mf6YDH/J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D3C7C32781; Sun, 26 May 2024 09:43:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716716631; bh=4Hx/U7MiYIQ+eFnMWjsQEcNrONO+JzOpAm5p7GNLqT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mf6YDH/Jbluhd0jBFucAIme0m1vfYoz0kKMb5sfpqkuAiIXFc+HpeUcPoUl/90TM7 eK+7/j669KyrqpeVqGijG5KnWJuf77Y3hUQHRngk/MD6GD8A9n5vRVWtLkaljVqz71 16C2vP5tug+T00j2W9lty8/GjhZXNFjD4FCfziwpHbBgkc+/1N1jHiqEpRw9tR4MVo gAov8BUF/3YU0w7K8kHxS9zxh+HpWvPFe6J/cnpxeHFik4nFhhjcHyJXVAZxvrwTHw Y61MzYE2op7Vo76UcRIE7VEtPnECqQ/xM18TuppFql6khPQzzsgBbvRmsxPq0gH4sa ugymWNZFRsPZg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Justin Stitt , Christoph Hellwig , Jens Axboe , Sasha Levin , nathan@kernel.org, linux-block@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 5.10 5/5] block/ioctl: prefer different overflow check Date: Sun, 26 May 2024 05:43:41 -0400 Message-ID: <20240526094342.3413841-5-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240526094342.3413841-1-sashal@kernel.org> References: <20240526094342.3413841-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.217 Content-Transfer-Encoding: 8bit From: Justin Stitt [ Upstream commit ccb326b5f9e623eb7f130fbbf2505ec0e2dcaff9 ] Running syzkaller with the newly reintroduced signed integer overflow sanitizer shows this report: [ 62.982337] ------------[ cut here ]------------ [ 62.985692] cgroup: Invalid name [ 62.986211] UBSAN: signed-integer-overflow in ../block/ioctl.c:36:46 [ 62.989370] 9pnet_fd: p9_fd_create_tcp (7343): problem connecting socket to 127.0.0.1 [ 62.992992] 9223372036854775807 + 4095 cannot be represented in type 'long long' [ 62.997827] 9pnet_fd: p9_fd_create_tcp (7345): problem connecting socket to 127.0.0.1 [ 62.999369] random: crng reseeded on system resumption [ 63.000634] GUP no longer grows the stack in syz-executor.2 (7353): 20002000-20003000 (20001000) [ 63.000668] CPU: 0 PID: 7353 Comm: syz-executor.2 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 63.000677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 63.000682] Call Trace: [ 63.000686] [ 63.000731] dump_stack_lvl+0x93/0xd0 [ 63.000919] __get_user_pages+0x903/0xd30 [ 63.001030] __gup_longterm_locked+0x153e/0x1ba0 [ 63.001041] ? _raw_read_unlock_irqrestore+0x17/0x50 [ 63.001072] ? try_get_folio+0x29c/0x2d0 [ 63.001083] internal_get_user_pages_fast+0x1119/0x1530 [ 63.001109] iov_iter_extract_pages+0x23b/0x580 [ 63.001206] bio_iov_iter_get_pages+0x4de/0x1220 [ 63.001235] iomap_dio_bio_iter+0x9b6/0x1410 [ 63.001297] __iomap_dio_rw+0xab4/0x1810 [ 63.001316] iomap_dio_rw+0x45/0xa0 [ 63.001328] ext4_file_write_iter+0xdde/0x1390 [ 63.001372] vfs_write+0x599/0xbd0 [ 63.001394] ksys_write+0xc8/0x190 [ 63.001403] do_syscall_64+0xd4/0x1b0 [ 63.001421] ? arch_exit_to_user_mode_prepare+0x3a/0x60 [ 63.001479] entry_SYSCALL_64_after_hwframe+0x6f/0x77 [ 63.001535] RIP: 0033:0x7f7fd3ebf539 [ 63.001551] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 63.001562] RSP: 002b:00007f7fd32570c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 63.001584] RAX: ffffffffffffffda RBX: 00007f7fd3ff3f80 RCX: 00007f7fd3ebf539 [ 63.001590] RDX: 4db6d1e4f7e43360 RSI: 0000000020000000 RDI: 0000000000000004 [ 63.001595] RBP: 00007f7fd3f1e496 R08: 0000000000000000 R09: 0000000000000000 [ 63.001599] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 63.001604] R13: 0000000000000006 R14: 00007f7fd3ff3f80 R15: 00007ffd415ad2b8 ... [ 63.018142] ---[ end trace ]--- Historically, the signed integer overflow sanitizer did not work in the kernel due to its interaction with `-fwrapv` but this has since been changed [1] in the newest version of Clang; It was re-enabled in the kernel with Commit 557f8c582a9ba8ab ("ubsan: Reintroduce signed overflow sanitizer"). Let's rework this overflow checking logic to not actually perform an overflow during the check itself, thus avoiding the UBSAN splat. [1]: https://github.com/llvm/llvm-project/pull/82432 Signed-off-by: Justin Stitt Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240507-b4-sio-block-ioctl-v3-1-ba0c2b32275e@google.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/ioctl.c b/block/ioctl.c index bc97698e0e8a3..11e692741f17c 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -32,7 +32,7 @@ static int blkpg_do_ioctl(struct block_device *bdev, if (op == BLKPG_DEL_PARTITION) return bdev_del_partition(bdev, p.pno); - if (p.start < 0 || p.length <= 0 || p.start + p.length < 0) + if (p.start < 0 || p.length <= 0 || LLONG_MAX - p.length < p.start) return -EINVAL; /* Check that the partition is aligned to the block size */ if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev))) -- 2.43.0