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 5E5F010E3 for ; Tue, 20 Jun 2023 02:00:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D300C433C8; Tue, 20 Jun 2023 02:00:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687226409; bh=q991Df6lElczcQfXTZH5AJGFVHbnOIKkuwwRkFJopok=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Bkkf5QRDS1XkG0z/mmLqUfLjSW2LOWrMQdW2D7mXxEDcgkaWkYEnCI3MpgJ7bksDa yF+0Pq9gplP94mSjFQ+lNBsb9a8cG4IvRW+F8LWiwIW3yi5odKhSIfk7Zo+pwM3VeB ADgR6RL6hEhxDyaaNOhSz6q98aR00gFrRy+0uSR0GXAygMyYJavRuY6DJabpCQjyab 5dBRywIdOcFPnAtM+cm9P8GgKcANbCmVG3GeSYF5RdfwTJswJyGkZ/j7ZgSH2wT1pD uYvkb91Gu8883KZZyE3ISjXeMGzhhi1E1mQugsdTIx9sJJwBGwrTX92JK+3lFwrwzY pfimmOJ5BtQQA== Message-ID: <483161ce-f36b-a0d8-0239-6c68ea34e92f@kernel.org> Date: Mon, 19 Jun 2023 19:00:08 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH net-next] net: remove sk_is_ipmr() and sk_is_icmpv6() helpers Content-Language: en-US To: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, syzbot , Breno Leitao , Willem de Bruijn , Kuniyuki Iwashima References: <20230619124336.651528-1-edumazet@google.com> From: David Ahern In-Reply-To: <20230619124336.651528-1-edumazet@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/19/23 5:43 AM, Eric Dumazet wrote: > Blamed commit added these helpers for sake of detecting RAW > sockets specific ioctl. > > syzbot complained about it [1]. > > Issue here is that RAW sockets could pretend there was no need > to call ipmr_sk_ioctl() > > Regardless of inet_sk(sk)->inet_num, we must be prepared > for ipmr_ioctl() being called later. This must happen > from ipmr_sk_ioctl() context only. > > We could add a safety check in ipmr_ioctl() at the risk of breaking > applications. > > Instead, remove sk_is_ipmr() and sk_is_icmpv6() because their > name would be misleading, once we change their implementation. > > [1] > BUG: KASAN: stack-out-of-bounds in ipmr_ioctl+0xb12/0xbd0 net/ipv4/ipmr.c:1654 > Read of size 4 at addr ffffc90003aefae4 by task syz-executor105/5004 > > CPU: 0 PID: 5004 Comm: syz-executor105 Not tainted 6.4.0-rc6-syzkaller-01304-gc08afcdcf952 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 > Call Trace: > > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 > print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 > print_report mm/kasan/report.c:462 [inline] > kasan_report+0x11c/0x130 mm/kasan/report.c:572 > ipmr_ioctl+0xb12/0xbd0 net/ipv4/ipmr.c:1654 > raw_ioctl+0x4e/0x1e0 net/ipv4/raw.c:881 > sock_ioctl_out net/core/sock.c:4186 [inline] > sk_ioctl+0x151/0x440 net/core/sock.c:4214 > inet_ioctl+0x18c/0x380 net/ipv4/af_inet.c:1001 > sock_do_ioctl+0xcc/0x230 net/socket.c:1189 > sock_ioctl+0x1f8/0x680 net/socket.c:1306 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:870 [inline] > __se_sys_ioctl fs/ioctl.c:856 [inline] > __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f2944bf6ad9 > Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffd8897a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2944bf6ad9 > RDX: 0000000000000000 RSI: 00000000000089e1 RDI: 0000000000000003 > RBP: 00007f2944bbac80 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2944bbad10 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > The buggy address belongs to stack of task syz-executor105/5004 > and is located at offset 36 in frame: > sk_ioctl+0x0/0x440 net/core/sock.c:4172 > > This frame has 2 objects: > [32, 36) 'karg' > [48, 88) 'buffer' > > Fixes: e1d001fa5b47 ("net: ioctl: Use kernel memory on protocol ioctl callbacks") > Reported-by: syzbot > Signed-off-by: Eric Dumazet > Cc: Breno Leitao > Cc: Willem de Bruijn > Cc: David Ahern > Cc: Kuniyuki Iwashima > --- > include/linux/icmpv6.h | 6 ------ > include/linux/mroute.h | 11 ----------- > net/core/sock.c | 4 ++-- > 3 files changed, 2 insertions(+), 19 deletions(-) > > diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h > index 1fe33e6741cca2685082da214afbc94c7974f4ce..db0f4fcfdaf4f138d75dc6c4073cb286364f2923 100644 > --- a/include/linux/icmpv6.h > +++ b/include/linux/icmpv6.h > @@ -111,10 +111,4 @@ static inline bool icmpv6_is_err(int type) > return false; > } > > -static inline int sk_is_icmpv6(struct sock *sk) > -{ > - return sk->sk_family == AF_INET6 && > - inet_sk(sk)->inet_num == IPPROTO_ICMPV6; > -} > - > #endif > diff --git a/include/linux/mroute.h b/include/linux/mroute.h > index 94c6e6f549f0a503f6707d1175f1c47a0f0cd887..4c5003afee6c51962bc13879978845bc7daf08fa 100644 > --- a/include/linux/mroute.h > +++ b/include/linux/mroute.h > @@ -16,12 +16,6 @@ static inline int ip_mroute_opt(int opt) > return opt >= MRT_BASE && opt <= MRT_MAX; > } > > -static inline int sk_is_ipmr(struct sock *sk) > -{ > - return sk->sk_family == AF_INET && > - inet_sk(sk)->inet_num == IPPROTO_IGMP; > -} > - > int ip_mroute_setsockopt(struct sock *, int, sockptr_t, unsigned int); > int ip_mroute_getsockopt(struct sock *, int, sockptr_t, sockptr_t); > int ipmr_ioctl(struct sock *sk, int cmd, void *arg); > @@ -57,11 +51,6 @@ static inline int ip_mroute_opt(int opt) > return 0; > } > > -static inline int sk_is_ipmr(struct sock *sk) > -{ > - return 0; > -} > - > static inline bool ipmr_rule_default(const struct fib_rule *rule) > { > return true; > diff --git a/net/core/sock.c b/net/core/sock.c > index cff3e82514d17513bc96300dc18014083a0d7ea7..8ec8f4c9911f2a6dd3dd946798d512394d62a861 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -4199,9 +4199,9 @@ int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) > { > int rc = 1; > > - if (sk_is_ipmr(sk)) > + if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET) > rc = ipmr_sk_ioctl(sk, cmd, arg); > - else if (sk_is_icmpv6(sk)) > + else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6) > rc = ip6mr_sk_ioctl(sk, cmd, arg); > else if (sk_is_phonet(sk)) > rc = phonet_sk_ioctl(sk, cmd, arg); I was staring at the type when reviewing the original patch; I was expecting to see RAW based on where ipmr_ioctl (and v6 version) is called. That's why I asked about the testing of the patch, so I am not surprised by this followup. Reviewed-by: David Ahern