From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baozeng Ding Subject: Re: BUG: net/netfilter: KASAN: stack-out-of-bounds in tcp_packet Date: Mon, 28 Mar 2016 21:14:09 +0800 Message-ID: <56F92E21.30509@gmail.com> References: <56F7D3AD.10003@gmail.com> <56F8987B.5030501@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8BIT Cc: Pablo Neira Ayuso , Patrick McHardy , David Miller , netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: Jozsef Kadlecsik Return-path: In-Reply-To: <56F8987B.5030501@gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org On 2016/3/28 10:35, Baozeng Ding wrote: > > > On 2016/3/28 6:25, Jozsef Kadlecsik wrote: >> On Mon, 28 Mar 2016, Jozsef Kadlecsik wrote: >> >>> On Sun, 27 Mar 2016, Baozeng Ding wrote: >>> >>>> The following program triggers stack-out-of-bounds in tcp_packet. The >>>> kernel version is 4.5 (on Mar 16 commit >>>> 09fd671ccb2475436bd5f597f751ca4a7d177aea). >>>> Uncovered with syzkaller. Thanks. >>>> >>>> ================================================================== >>>> BUG: KASAN: stack-out-of-bounds in tcp_packet+0x4b77/0x51c0 at addr >>>> ffff8800a45df3c8 >>>> Read of size 1 by task 0327/11132 >>>> page:ffffea00029177c0 count:0 mapcount:0 mapping: (null) index:0x0 >>>> flags: 0x1fffc0000000000() >>>> page dumped because: kasan: bad access detected >>>> CPU: 1 PID: 11132 Comm: 0327 Tainted: G B 4.5.0+ #12 >>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >>>> rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 >>>> 0000000000000001 ffff8800a45df148 ffffffff82945051 ffff8800a45df1d8 >>>> ffff8800a45df3c8 0000000000000027 0000000000000001 ffff8800a45df1c8 >>>> ffffffff81709f88 ffff8800b4f7e3d0 0000000000000028 0000000000000286 >>>> Call Trace: >>>> [< inline >] __dump_stack /kernel/lib/dump_stack.c:15 >>>> [] dump_stack+0xb3/0x112 /kernel/lib/dump_stack.c:51 >>>> [< inline >] print_address_description >>>> /kernel/mm/kasan/report.c:150 >>>> [] kasan_report_error+0x4f8/0x530 >>>> /kernel/mm/kasan/report.c:236 >>>> [] ? skb_copy_bits+0x49d/0x6d0 >>>> /kernel/net/core/skbuff.c:1675 >>>> [< inline >] ? spin_lock_bh >>>> /kernel/include/linux/spinlock.h:307 >>>> [] ? tcp_packet+0x1c9/0x51c0 >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:833 >>>> [< inline >] kasan_report /kernel/mm/kasan/report.c:259 >>>> [] __asan_report_load1_noabort+0x3e/0x40 >>>> /kernel/mm/kasan/report.c:277 >>>> [< inline >] ? tcp_sack >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:473 >>>> [< inline >] ? tcp_in_window >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:527 >>>> [] ? tcp_packet+0x4b77/0x51c0 >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:1036 >>>> [< inline >] tcp_sack >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:473 >>>> [< inline >] tcp_in_window >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:527 >>>> [] tcp_packet+0x4b77/0x51c0 >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:1036 >>>> [] ? memset+0x28/0x30 /kernel/mm/kasan/kasan.c:302 >>>> [] ? tcp_new+0x1a4/0xc20 >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:1122 >>>> [< inline >] ? build_report /kernel/include/net/netlink.h:499 >>>> [] ? xfrm_send_report+0x426/0x450 >>>> /kernel/net/xfrm/xfrm_user.c:3039 >>>> [] ? tcp_new+0xc20/0xc20 >>>> /kernel/net/netfilter/nf_conntrack_proto_tcp.c:1169 >>>> [] ? init_conntrack+0xca/0x9e0 >>>> /kernel/net/netfilter/nf_conntrack_core.c:972 >>>> [] ? nf_conntrack_alloc+0x40/0x40 >>>> /kernel/net/netfilter/nf_conntrack_core.c:903 >>>> [] ? tcp_init_net+0x6e0/0x6e0 >>>> /kernel/include/net/netfilter/nf_conntrack_l4proto.h:137 >>>> [] ? ipv4_get_l4proto+0x262/0x390 >>>> /kernel/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c:89 >>>> [] ? nf_ct_get_tuple+0xaf/0x190 >>>> /kernel/net/netfilter/nf_conntrack_core.c:197 >>>> [] nf_conntrack_in+0x8ee/0x1170 >>>> /kernel/net/netfilter/nf_conntrack_core.c:1177 >>>> [] ? init_conntrack+0x9e0/0x9e0 >>>> /kernel/net/netfilter/nf_conntrack_core.c:287 >>>> [] ? ipt_do_table+0xa16/0x1260 >>>> /kernel/net/ipv4/netfilter/ip_tables.c:423 >>>> [] ? trace_hardirqs_on+0xd/0x10 >>>> /kernel/kernel/locking/lockdep.c:2635 >>>> [] ? __local_bh_enable_ip+0x6b/0xc0 >>>> /kernel/kernel/softirq.c:175 >>>> [] ? check_entry.isra.4+0x190/0x190 >>>> /kernel/net/ipv6/netfilter/ip6_tables.c:594 >>>> [] ? ip_reply_glue_bits+0xc0/0xc0 >>>> /kernel/net/ipv4/ip_output.c:1530 >>>> [] ipv4_conntrack_local+0x14e/0x1a0 >>>> /kernel/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c:161 >>>> [] ? iptable_raw_hook+0x9d/0x1e0 >>>> /kernel/net/ipv4/netfilter/iptable_raw.c:32 >>>> [] nf_iterate+0x15d/0x230 >>>> /kernel/net/netfilter/core.c:274 >>>> [] ? nf_iterate+0x230/0x230 >>>> /kernel/net/netfilter/core.c:268 >>>> [] nf_hook_slow+0x1ad/0x310 >>>> /kernel/net/netfilter/core.c:306 >>>> [] ? nf_iterate+0x230/0x230 >>>> /kernel/net/netfilter/core.c:268 >>>> [] ? nf_iterate+0x230/0x230 >>>> /kernel/net/netfilter/core.c:268 >>>> [] ? prandom_u32+0x24/0x30 /kernel/lib/random32.c:83 >>>> [] ? ip_idents_reserve+0x9f/0xf0 >>>> /kernel/net/ipv4/route.c:484 >>>> [< inline >] nf_hook_thresh >>>> /kernel/include/linux/netfilter.h:187 >>>> [< inline >] nf_hook /kernel/include/linux/netfilter.h:197 >>>> [] __ip_local_out+0x263/0x3c0 >>>> /kernel/net/ipv4/ip_output.c:104 >>>> [] ? ip_finish_output+0xd00/0xd00 >>>> /kernel/include/net/ip.h:322 >>>> [] ? __ip_flush_pending_frames.isra.45+0x2e0/0x2e0 >>>> /kernel/net/ipv4/ip_output.c:1337 >>>> [] ? __ip_make_skb+0xfe6/0x1610 >>>> /kernel/net/ipv4/ip_output.c:1436 >>>> [] ip_local_out+0x2d/0x1c0 >>>> /kernel/net/ipv4/ip_output.c:113 >>>> [] ip_send_skb+0x3c/0xc0 >>>> /kernel/net/ipv4/ip_output.c:1443 >>>> [] ip_push_pending_frames+0x64/0x80 >>>> /kernel/net/ipv4/ip_output.c:1463 >>>> [< inline >] rcu_read_unlock >>>> /kernel/include/linux/rcupdate.h:922 >>>> [] raw_sendmsg+0x17bb/0x25c0 >>>> /kernel/net/ieee802154/socket.c:53 >>>> [] ? dst_output+0x190/0x190 >>>> /kernel/include/net/dst.h:492 >>>> [< inline >] ? trace_mm_page_alloc >>>> /kernel/include/trace/events/kmem.h:217 >>>> [] ? __alloc_pages_nodemask+0x559/0x16b0 >>>> /kernel/mm/page_alloc.c:3368 >>>> [] ? debug_check_no_locks_freed+0x290/0x290 >>>> /kernel/kernel/locking/lockdep.c:4104 >>>> [] ? is_module_text_address+0x10/0x20 >>>> /kernel/kernel/module.c:4057 >>>> [] ? __kernel_text_address+0x73/0xa0 >>>> /kernel/kernel/extable.c:103 >>>> [] ? debug_check_no_locks_freed+0x290/0x290 >>>> /kernel/kernel/locking/lockdep.c:4104 >>>> [] ? debug_check_no_locks_freed+0x290/0x290 >>>> /kernel/kernel/locking/lockdep.c:4104 >>>> [] ? trace_hardirqs_on+0xd/0x10 >>>> /kernel/kernel/locking/lockdep.c:2635 >>>> [] ? debug_check_no_locks_freed+0x290/0x290 >>>> /kernel/kernel/locking/lockdep.c:4104 >>>> [< inline >] ? sock_rps_record_flow >>>> /kernel/include/net/sock.h:874 >>>> [] ? inet_sendmsg+0x73/0x4c0 >>>> /kernel/net/ipv4/af_inet.c:729 >>>> [< inline >] ? rcu_read_unlock >>>> /kernel/include/linux/rcupdate.h:922 >>>> [< inline >] ? sock_rps_record_flow_hash >>>> /kernel/include/net/sock.h:867 >>>> [< inline >] ? sock_rps_record_flow >>>> /kernel/include/net/sock.h:874 >>>> [] ? inet_sendmsg+0x1fa/0x4c0 >>>> /kernel/net/ipv4/af_inet.c:729 >>>> [] inet_sendmsg+0x2f5/0x4c0 >>>> /kernel/net/ipv4/af_inet.c:736 >>>> [< inline >] ? sock_rps_record_flow >>>> /kernel/include/net/sock.h:874 >>>> [] ? inet_sendmsg+0x73/0x4c0 >>>> /kernel/net/ipv4/af_inet.c:729 >>>> [] ? inet_recvmsg+0x4a0/0x4a0 >>>> /kernel/include/linux/compiler.h:222 >>>> [< inline >] sock_sendmsg_nosec /kernel/net/socket.c:611 >>>> [] sock_sendmsg+0xca/0x110 /kernel/net/socket.c:621 >>>> [] SYSC_sendto+0x208/0x350 /kernel/net/socket.c:1651 >>>> [] ? SYSC_connect+0x2e0/0x2e0 >>>> /kernel/net/socket.c:1543 >>>> [] ? __pmd_alloc+0x350/0x350 >>>> /kernel/mm/memory.c:3928 >>>> [] ? __do_page_fault+0x2ab/0x8e0 >>>> /kernel/arch/x86/mm/fault.c:1184 >>>> [] ? __do_page_fault+0x3a0/0x8e0 >>>> /kernel/arch/x86/mm/fault.c:1271 >>>> [] ? up_read+0x1a/0x40 >>>> /kernel/kernel/locking/rwsem.c:79 >>>> [] ? __do_page_fault+0x199/0x8e0 >>>> /kernel/arch/x86/mm/fault.c:1187 >>>> [] SyS_sendto+0x40/0x50 /kernel/net/socket.c:1619 >>>> [] entry_SYSCALL_64_fastpath+0x23/0xc1 >>>> /kernel/arch/x86/entry/entry_64.S:207 >>>> Memory state around the buggy address: >>>> ffff8800a45df280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>>> ffff8800a45df300: f1 f1 f1 f1 00 00 04 f4 f2 f2 f2 f2 00 00 04 f4 >>>>> ffff8800a45df380: f2 f2 f2 f2 00 00 00 00 00 f4 f4 f4 f3 f3 f3 f3 >>>> ^ >>>> ffff8800a45df400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>>> ffff8800a45df480: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 01 f4 f4 f4 >>>> ================================================================== >>>> >>>> #include >>>> #include >>>> #include >>>> #include >>>> #include >>>> #include >>>> #include >>>> #include >>>> int main() >>>> { >>>> mmap((void *)0x20000000ul, 0x19000ul, PROT_READ|PROT_WRITE, >>>> MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); >>>> int sock = socket(AF_INET, SOCK_RAW, IPPROTO_TCP); >>>> int sock_dup = dup(sock); >>>> memcpy((void*)0x2000b000, >>>> "\x11\xaf\x7d\x99\x91\x3c\x87\x34\x85\x18\xc4\xd6\xf2\x30\x0a", 15); >>>> *(uint16_t*)0x20002fec = (uint16_t)0x2; >>>> *(uint16_t*)0x20002fee = (uint16_t)0x11ab; >>>> *(uint32_t*)0x20002ff0 = (uint32_t)0x100007f; >>>> sendto(sock_dup, (void *)0x2000b000ul, 0xful, 0x8800ul, >>>> (struct >>>> sockaddr *)0x20002fe4ul, 0x1cul); >>>> memcpy((void*)0x2001504f, >>>> "\x7e\xb1\x52\x5b\x78\x85\x27\xe7\xcc\x3d\xf5\x18\x1b\xba\xda\x97\x6c\x18\x72\x0c\xd2\x0a\xa6\x77\xb7\x8b\xa2\xd2\x1d\xf0\x6b\xf6\x1a\x27\x6b\x98\x3e\x0b\x49\x8d\x54\x6e\x9e\xbb\x21\x4a\x72\x79\x1f\x82\xaf\x89\x2c\xf6\xd3\xc9\xd7\xed\x18\x29\x4d\x2e\x03\x15\xe2\x03\x14\xd0\xac\xa5\x81\x37\x73\x88\xa9\xf5\x08\xe5\xef\x5b\x56\xb7\x18\x8f\xe6\x19\xea\x91\x82\x23\xdd\x2c\x5c\xa5\xf0\xfc\xd8\xe2\x8b\x91\x48\x70\x24\xed\xae\xf9\x06\xac\xc4\x53\x01\xc3\xf5\xa3\x10\xef\xf1\xa6\x2b\xae\x72\xc7\x1a\x02\xee\x78\xcd\xd1\x7e\x8c\x9c\x1a\x36\xc7\xd4\x7c\x82\x64\xf7\x8b\x5a\xb0\x72\xa8\x87\x3c\xdc\xd0\xba\xfe\x70\x7d\x8c\x23\x78\xad\x7c\x31\x04\xec\xab\x1e\x4c\xee\xae\x84\xd8\x1a\x1d\x85\xa5\x57\xa8\x24\x53\x08\x1c\x4f\xda\x49\xe5\x3a\x99\x8c\x29\xa1\xed\x4b\x42\x7a\x15\x48\x2a\x22\x3b\x81\xfe\x47\x 74\xc1\x2f\x64\xcf\x10\xd4\x71\x72\x50\x71\xd7\xf6\xb0\xca\x41\x9a\x5e\x3e\xe4\x31\x19\xd1\x19\x46\x20\x66\x4c\x2f\xea\x76\x17\x2d\x94", >>>> >>>> 232); >>>> *(uint16_t*)0x2001501c = (uint16_t)0xa; >>>> *(uint16_t*)0x2001501e = (uint16_t)0x11ab; >>>> *(uint32_t*)0x20015020 = (uint32_t)0xbdc; >>>> *(uint32_t*)0x20015024 = (uint32_t)0x0; >>>> *(uint32_t*)0x20015028 = (uint32_t)0x0; >>>> *(uint32_t*)0x2001502c = (uint32_t)0x0; >>>> *(uint32_t*)0x20015030 = (uint32_t)0x1000000; >>>> *(uint32_t*)0x20015034 = (uint32_t)0x3; >>>> sendto(sock_dup, (void *)0x2001504ful, 0xe8ul, 0x880ul, >>>> (struct >>>> sockaddr *)0x20015000ul, 0x1cul); >>>> return 0; >>>> } >> Actually, in order to fix the non-conntrack case too, I believe the next >> patch is required: >> >> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c >> index d4c5115..365f4fb 100644 >> --- a/net/ipv4/tcp_input.c >> +++ b/net/ipv4/tcp_input.c >> @@ -3716,6 +3716,8 @@ void tcp_parse_options(const struct sk_buff *skb, >> length--; >> continue; >> default: >> + if (length < 2) >> + return; >> opsize = *ptr++; >> if (opsize < 2) /* "silly options" */ >> return; >> @@ -3873,6 +3875,8 @@ const u8 *tcp_parse_md5sig_option(const struct >> tcphdr *th) >> length--; >> continue; >> default: >> + if (length < 2) >> + return; >> opsize = *ptr++; >> if (opsize < 2 || opsize > length) >> return NULL; >> diff --git a/net/netfilter/nf_conntrack_proto_tcp.c >> b/net/netfilter/nf_conntrack_proto_tcp.c >> index 278f3b9..7cc1d9c 100644 >> --- a/net/netfilter/nf_conntrack_proto_tcp.c >> +++ b/net/netfilter/nf_conntrack_proto_tcp.c >> @@ -410,6 +410,8 @@ static void tcp_options(const struct sk_buff *skb, >> length--; >> continue; >> default: >> + if (length < 2) >> + return; >> opsize=*ptr++; >> if (opsize < 2) /* "silly options" */ >> return; >> @@ -470,6 +472,8 @@ static void tcp_sack(const struct sk_buff *skb, >> unsigned int dataoff, >> length--; >> continue; >> default: >> + if (length < 2) >> + return; >> opsize = *ptr++; >> if (opsize < 2) /* "silly options" */ >> return; I tested with the patch and it fixed the bug. Thanks. >> Best regards, >> Jozsef >> - >> E-mail : kadlec@blackhole.kfki.hu, kadlecsik.jozsef@wigner.mta.hu >> PGP key : http://www.kfki.hu/~kadlec/pgp_public_key.txt >> Address : Wigner Research Centre for Physics, Hungarian Academy of >> Sciences >> H-1525 Budapest 114, POB. 49, Hungary > >