On Mon, Oct 30, 2017 at 7:41 PM, Cong Wang <xiyou.wangc...@gmail.com> wrote: > On Mon, Oct 30, 2017 at 8:34 AM, syzbot > <bot+1aa412fe58f4059538c0204a0f096524e6dce...@syzkaller.appspotmail.com> > wrote: >> Hello, >> >> syzkaller hit the following crash on >> 4dc12ffeaeac939097a3f55c881d3dc3523dff0c >> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached >> Raw console output is attached. >> >> skbuff: bad partial csum: csum=53081/14726 len=2273 >> ================================================================== >> BUG: KASAN: use-after-free in ipv6_get_dsfield include/net/dsfield.h:23 >> [inline] >> BUG: KASAN: use-after-free in ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline] >> BUG: KASAN: use-after-free in sit_tunnel_xmit+0x2a41/0x3130 >> net/ipv6/sit.c:1016 >> Read of size 2 at addr ffff8801c64afd00 by task syz-executor3/16942 >> >> CPU: 0 PID: 16942 Comm: syz-executor3 Not tainted 4.14.0-rc5+ #97 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:16 [inline] >> dump_stack+0x194/0x257 lib/dump_stack.c:52 >> print_address_description+0x73/0x250 mm/kasan/report.c:252 >> kasan_report_error mm/kasan/report.c:351 [inline] >> kasan_report+0x25b/0x340 mm/kasan/report.c:409 >> __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428 >> ipv6_get_dsfield include/net/dsfield.h:23 [inline] >> ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline] >> sit_tunnel_xmit+0x2a41/0x3130 net/ipv6/sit.c:1016 >> __netdev_start_xmit include/linux/netdevice.h:4022 [inline] >> netdev_start_xmit include/linux/netdevice.h:4031 [inline] >> xmit_one net/core/dev.c:3008 [inline] >> dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 >> __dev_queue_xmit+0x17d2/0x2070 net/core/dev.c:3505 >> dev_queue_xmit+0x17/0x20 net/core/dev.c:3538 >> neigh_direct_output+0x15/0x20 net/core/neighbour.c:1390 >> neigh_output include/net/neighbour.h:481 [inline] >> ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120 >> ip6_fragment+0x25ae/0x3420 net/ipv6/ip6_output.c:723 >> ip6_finish_output+0x319/0x920 net/ipv6/ip6_output.c:144 >> NF_HOOK_COND include/linux/netfilter.h:238 [inline] >> ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163 >> dst_output include/net/dst.h:459 [inline] >> ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176 >> ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1658 >> ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1678 >> rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] >> rawv6_sendmsg+0x2eb9/0x3e40 net/ipv6/raw.c:935 >> inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 >> sock_sendmsg_nosec net/socket.c:633 [inline] >> sock_sendmsg+0xca/0x110 net/socket.c:643 >> SYSC_sendto+0x352/0x5a0 net/socket.c:1750 >> SyS_sendto+0x40/0x50 net/socket.c:1718 >> entry_SYSCALL_64_fastpath+0x1f/0xbe >> RIP: 0033:0x452869 >> RSP: 002b:00007fe3c12e5be8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c >> RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452869 >> RDX: 00000000000007f1 RSI: 000000002013b7ff RDI: 0000000000000014 >> RBP: 0000000000000161 R08: 00000000204e8fe4 R09: 000000000000001c >> R10: 0000000001000000 R11: 0000000000000212 R12: 00000000006f01b8 >> R13: 00000000ffffffff R14: 00007fe3c12e66d4 R15: 0000000000000017 >> >> Allocated by task 16924: >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 >> __do_kmalloc_node mm/slab.c:3689 [inline] >> __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3703 >> __kmalloc_reserve.isra.40+0x41/0xd0 net/core/skbuff.c:138 >> __alloc_skb+0x13b/0x780 net/core/skbuff.c:206 >> alloc_skb include/linux/skbuff.h:985 [inline] >> sock_wmalloc+0x140/0x1d0 net/core/sock.c:1932 >> __ip6_append_data.isra.43+0x2681/0x3340 net/ipv6/ip6_output.c:1397 >> ip6_append_data+0x189/0x290 net/ipv6/ip6_output.c:1552 >> rawv6_sendmsg+0x1dd9/0x3e40 net/ipv6/raw.c:928 >> inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 >> sock_sendmsg_nosec net/socket.c:633 [inline] >> sock_sendmsg+0xca/0x110 net/socket.c:643 >> SYSC_sendto+0x352/0x5a0 net/socket.c:1750 >> SyS_sendto+0x40/0x50 net/socket.c:1718 >> entry_SYSCALL_64_fastpath+0x1f/0xbe >> >> Freed by task 16942: >> save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 >> save_stack+0x43/0xd0 mm/kasan/kasan.c:447 >> set_track mm/kasan/kasan.c:459 [inline] >> kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 >> __cache_free mm/slab.c:3503 [inline] >> kfree+0xca/0x250 mm/slab.c:3820 >> skb_free_head+0x74/0xb0 net/core/skbuff.c:554 >> pskb_expand_head+0x36b/0x1210 net/core/skbuff.c:1494 >> __pskb_pull_tail+0x14a/0x17c0 net/core/skbuff.c:1877 >> pskb_may_pull include/linux/skbuff.h:2102 [inline] >> _decode_session6+0x8a4/0x1100 net/ipv6/xfrm6_policy.c:148 > > Looks like we should indicate error by returning some int > for afinfo->decode_session().
Cong, do you want to do something with this bug? Otherwise I want to close this as part of old bug bankruptcy. >> __xfrm_decode_session+0x63/0x100 net/xfrm/xfrm_policy.c:2343 >> xfrm_decode_session_reverse include/net/xfrm.h:1181 [inline] >> icmpv6_route_lookup+0x343/0x640 net/ipv6/icmp.c:372 >> icmp6_send+0x1569/0x25b0 net/ipv6/icmp.c:551 >> icmpv6_send+0x142/0x280 net/ipv6/ip6_icmp.c:42 >> ip6_link_failure+0x94/0x580 net/ipv6/route.c:1997 >> dst_link_failure include/net/dst.h:442 [inline] >> ipip6_tunnel_xmit net/ipv6/sit.c:940 [inline] >> sit_tunnel_xmit+0x244f/0x3130 net/ipv6/sit.c:1016 >> __netdev_start_xmit include/linux/netdevice.h:4022 [inline] >> netdev_start_xmit include/linux/netdevice.h:4031 [inline] >> xmit_one net/core/dev.c:3008 [inline] >> dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 >> __dev_queue_xmit+0x17d2/0x2070 net/core/dev.c:3505 >> dev_queue_xmit+0x17/0x20 net/core/dev.c:3538 >> neigh_direct_output+0x15/0x20 net/core/neighbour.c:1390 >> neigh_output include/net/neighbour.h:481 [inline] >> ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120 >> ip6_fragment+0x25ae/0x3420 net/ipv6/ip6_output.c:723 >> ip6_finish_output+0x319/0x920 net/ipv6/ip6_output.c:144 >> NF_HOOK_COND include/linux/netfilter.h:238 [inline] >> ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163 >> dst_output include/net/dst.h:459 [inline] >> ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176 >> ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1658 >> ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1678 >> rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] >> rawv6_sendmsg+0x2eb9/0x3e40 net/ipv6/raw.c:935 >> inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 >> sock_sendmsg_nosec net/socket.c:633 [inline] >> sock_sendmsg+0xca/0x110 net/socket.c:643 >> SYSC_sendto+0x352/0x5a0 net/socket.c:1750 >> SyS_sendto+0x40/0x50 net/socket.c:1718 >> entry_SYSCALL_64_fastpath+0x1f/0xbe >> >> The buggy address belongs to the object at ffff8801c64afc80 >> which belongs to the cache kmalloc-512 of size 512 >> The buggy address is located 128 bytes inside of >> 512-byte region [ffff8801c64afc80, ffff8801c64afe80) >> The buggy address belongs to the page: >> page:ffffea0007192bc0 count:1 mapcount:0 mapping:ffff8801c64af000 index:0x0 >> flags: 0x200000000000100(slab) >> raw: 0200000000000100 ffff8801c64af000 0000000000000000 0000000100000006 >> raw: ffffea00072d04e0 ffffea0007083fe0 ffff8801dac00940 0000000000000000 >> page dumped because: kasan: bad access detected >> >> Memory state around the buggy address: >> ffff8801c64afc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> ffff8801c64afc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >>> >>> ffff8801c64afd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ^ >> ffff8801c64afd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff8801c64afe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ================================================================== >> >> >> --- >> This bug is generated by a dumb bot. It may contain errors. >> See https://goo.gl/tpsmEJ for details. >> Direct all questions to syzkal...@googlegroups.com. >> >> syzbot will keep track of this bug report. >> Once a fix for this bug is committed, please reply to this email with: >> #syz fix: exact-commit-title >> To mark this as a duplicate of another syzbot report, please reply with: >> #syz dup: exact-subject-of-another-report >> If it's a one-off invalid bug report, please reply with: >> #syz invalid >> Note: if the crash happens again, it will cause creation of a new bug >> report. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/CAM_iQpVyf_%3DUFW5Oay9a15GD8QaXbgbPse333SWAivE%3Ddd%2BTXQ%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout.
