Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC22BC433EF for ; Sat, 27 Nov 2021 15:33:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347174AbhK0PhF (ORCPT ); Sat, 27 Nov 2021 10:37:05 -0500 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:38648 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347347AbhK0PfE (ORCPT ); Sat, 27 Nov 2021 10:35:04 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=cuibixuan@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0UyTp5Uj_1638027102; Received: from VM20210331-25.tbsite.net(mailfrom:cuibixuan@linux.alibaba.com fp:SMTPD_---0UyTp5Uj_1638027102) by smtp.aliyun-inc.com(127.0.0.1); Sat, 27 Nov 2021 23:31:46 +0800 From: Bixuan Cui To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org Cc: cuibixuan@linux.alibaba.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org Subject: [PATCH -next] bpf: Add oversize check before call kvmalloc() Date: Sat, 27 Nov 2021 23:31:42 +0800 Message-Id: <1638027102-22686-1-git-send-email-cuibixuan@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the oversize check. When the allocation is larger than what kvmalloc() supports, the following warning triggered: WARNING: CPU: 1 PID: 372 at mm/util.c:597 kvmalloc_node+0x111/0x120 mm/util.c:597 Modules linked in: CPU: 1 PID: 372 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvmalloc_node+0x111/0x120 mm/util.c:597 Code: 01 00 00 00 4c 89 e7 e8 7d f7 0c 00 49 89 c5 e9 69 ff ff ff e8 60 20 d1 ff 41 89 ed 41 81 cd 00 20 01 00 eb 95 e8 4f 20 d1 ff <0f> 0b e9 4c ff ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 36 RSP: 0018:ffffc90002bf7c98 EFLAGS: 00010216 RAX: 00000000000000ec RBX: 1ffff9200057ef9f RCX: ffffc9000ac63000 RDX: 0000000000040000 RSI: ffffffff81a6a621 RDI: 0000000000000003 RBP: 0000000000102cc0 R08: 000000007fffffff R09: 00000000ffffffff R10: ffffffff81a6a5de R11: 0000000000000000 R12: 00000000ffff9aaa R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007f05f2573700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f424000 CR3: 0000000027d2c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvmalloc include/linux/slab.h:741 [inline] map_lookup_elem kernel/bpf/syscall.c:1090 [inline] __sys_bpf+0x3a5b/0x5f00 kernel/bpf/syscall.c:4603 __do_sys_bpf kernel/bpf/syscall.c:4722 [inline] __se_sys_bpf kernel/bpf/syscall.c:4720 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4720 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The type of 'value_size' is u32, its value may exceed INT_MAX. Reported-by: syzbot+cecf5b7071a0dfb76530@syzkaller.appspotmail.com Signed-off-by: Bixuan Cui --- kernel/bpf/syscall.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 1033ee8..f5bc380 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1094,6 +1094,10 @@ static int map_lookup_elem(union bpf_attr *attr) } value_size = bpf_map_value_size(map); + if (value_size > INT_MAX) { + err = -EINVAL; + goto err_put; + } err = -ENOMEM; value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); -- 1.8.3.1