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 976F71C68E for ; Wed, 29 Nov 2023 23:04:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sLz2jk9v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B09CCC433C8; Wed, 29 Nov 2023 23:04:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701299069; bh=emw1V6qMKJGgft1Kf/BZN4BrcQRV5hu521wqg76vFDI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=sLz2jk9vLsRFVUAypz6yxPuAIlmjBarBrh26UXIUa7T5SuaGAYDTqpuMYfnX/yrNa UxMPGN4++JYitleADHFimwfM51apvZ7tt40RzHxYWhyrU5T6eX1IC2iejwfzZTdgCf UgTwoGxpIdNstETzqLgqZOUYxXzSMf44Uzdiss74nxQHshZBgHu111pC0hFF4Yx4ut lRuVXdsVUXcanvfy1zZHbOtahhXjL8E0Ot0jc9Zuu3QZ2wKhx9yXPUbHApyE2gtw9t C/duvj4lPo/X3gRo8u4wSO6XhqYB7rVpE2+vQVG0bO3bC4u2b3oad2Y3B61TktM3B2 WxFDx3uI2hqmg== Message-ID: <4930145b-7f45-4fb0-90cb-ff1d5e265abe@kernel.org> Date: Wed, 29 Nov 2023 16:04:27 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net] ipv6: fix potential NULL deref in fib6_add() To: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, syzbot , Wei Wang References: <20231129160630.3509216-1-edumazet@google.com> Content-Language: en-US From: David Ahern In-Reply-To: <20231129160630.3509216-1-edumazet@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/29/23 9:06 AM, Eric Dumazet wrote: > If fib6_find_prefix() returns NULL, we should silently fallback > using fib6_null_entry regardless of RT6_DEBUG value. > > syzbot reported: > > WARNING: CPU: 0 PID: 5477 at net/ipv6/ip6_fib.c:1516 fib6_add+0x310d/0x3fa0 net/ipv6/ip6_fib.c:1516 > Modules linked in: > CPU: 0 PID: 5477 Comm: syz-executor.0 Not tainted 6.7.0-rc2-syzkaller-00029-g9b6de136b5f0 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 > RIP: 0010:fib6_add+0x310d/0x3fa0 net/ipv6/ip6_fib.c:1516 > Code: 00 48 8b 54 24 68 e8 42 22 00 00 48 85 c0 74 14 49 89 c6 e8 d5 d3 c2 f7 eb 5d e8 ce d3 c2 f7 e9 ca 00 00 00 e8 c4 d3 c2 f7 90 <0f> 0b 90 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 38 80 3c 01 00 > RSP: 0018:ffffc90005067740 EFLAGS: 00010293 > RAX: ffffffff89cba5bc RBX: ffffc90005067ab0 RCX: ffff88801a2e9dc0 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 > RBP: ffffc90005067980 R08: ffffffff89cbca85 R09: 1ffff110040d4b85 > R10: dffffc0000000000 R11: ffffed10040d4b86 R12: 00000000ffffffff > R13: 1ffff110051c3904 R14: ffff8880206a5c00 R15: ffff888028e1c820 > FS: 00007f763783c6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f763783bff8 CR3: 000000007f74d000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > __ip6_ins_rt net/ipv6/route.c:1303 [inline] > ip6_route_add+0x88/0x120 net/ipv6/route.c:3847 > ipv6_route_ioctl+0x525/0x7b0 net/ipv6/route.c:4467 > inet6_ioctl+0x21a/0x270 net/ipv6/af_inet6.c:575 > sock_do_ioctl+0x152/0x460 net/socket.c:1220 > sock_ioctl+0x615/0x8c0 net/socket.c:1339 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:51 [inline] > do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82 > > Fixes: 7bbfe00e0252 ("ipv6: fix general protection fault in fib6_add()") > Reported-by: syzbot > Signed-off-by: Eric Dumazet > Cc: Wei Wang > --- > net/ipv6/ip6_fib.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > Reviewed-by: David Ahern