On Fri, Feb 2, 2018 at 3:21 AM, syzbot <syzbot+b2bf2652983d23734c5c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot hit the following crash on net-next commit > b2fe5fa68642860e7de76167c3111623aa0d5de1 (Wed Jan 31 22:31:10 2018 +0000) > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next > > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+b2bf2652983d23734c5c@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > skbuff: skb_over_panic: text:000000004b89f3be len:66136 put:66124 > head:00000000f255561a data:00000000ccb55e52 tail:0x10310 end:0x6c0 > dev:<NULL> >From the raw log, it should be a data chunk. But I couldn't see how len:66136 happened? considering that frag_point is always smaller than SCTP_MAX_CHUNK_LEN. > ------------[ cut here ]------------ > kernel BUG at net/core/skbuff.c:104! > invalid opcode: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 1 PID: 19738 Comm: syz-executor3 Not tainted 4.15.0+ #219 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:skb_panic+0x162/0x1f0 net/core/skbuff.c:100 > RSP: 0018:ffff8801c1a6e4e8 EFLAGS: 00010286 > RAX: 000000000000008f RBX: ffff8801d0090000 RCX: 0000000000000000 > RDX: 000000000000008f RSI: ffffc90003d53000 RDI: ffffed003834dc91 > RBP: ffff8801c1a6e550 R08: 1ffff1003834dc1f R09: 0000000000000000 > R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff863fe4e0 > R13: ffffffff85276640 R14: 000000000001024c R15: ffffffff863fdd20 > FS: 00007f69cd01b700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000718008 CR3: 00000001c71c7006 CR4: 00000000001606e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > skb_over_panic net/core/skbuff.c:109 [inline] > skb_put+0x18d/0x1d0 net/core/skbuff.c:1695 > skb_put_data include/linux/skbuff.h:2049 [inline] > sctp_packet_pack net/sctp/output.c:473 [inline] > sctp_packet_transmit+0x1180/0x3750 net/sctp/output.c:606 > sctp_outq_flush+0x121b/0x4060 net/sctp/outqueue.c:1197 > sctp_outq_uncork+0x5a/0x70 net/sctp/outqueue.c:776 > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1807 [inline] > sctp_side_effects net/sctp/sm_sideeffect.c:1210 [inline] > sctp_do_sm+0x4e0/0x6ed0 net/sctp/sm_sideeffect.c:1181 > sctp_primitive_SEND+0xa0/0xd0 net/sctp/primitive.c:178 > sctp_sendmsg+0x1894/0x35e0 net/sctp/socket.c:2029 > inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:640 > sock_write_iter+0x31a/0x5d0 net/socket.c:909 > call_write_iter include/linux/fs.h:1781 [inline] > do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 > do_iter_write+0x154/0x540 fs/read_write.c:932 > vfs_writev+0x18a/0x340 fs/read_write.c:977 > do_writev+0xfc/0x2a0 fs/read_write.c:1012 > SYSC_writev fs/read_write.c:1085 [inline] > SyS_writev+0x27/0x30 fs/read_write.c:1082 > entry_SYSCALL_64_fastpath+0x29/0xa0 > RIP: 0033:0x453299 > RSP: 002b:00007f69cd01ac58 EFLAGS: 00000212 ORIG_RAX: 0000000000000014 > RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 > RDX: 0000000000000001 RSI: 0000000020f7ffe0 RDI: 0000000000000013 > RBP: 00000000000005c5 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f7b18 > R13: 00000000ffffffff R14: 00007f69cd01b6d4 R15: 0000000000000000 > Code: 04 01 84 c0 74 04 3c 03 7e 23 8b 8b 80 00 00 00 41 57 48 c7 c7 60 dd > 3f 86 52 56 4c 89 ea 41 50 4c 89 e6 45 89 f0 e8 c6 d7 25 fd <0f> 0b 4c 89 4d > b8 4c 89 45 c0 48 89 75 c8 48 89 55 d0 e8 47 53 > RIP: skb_panic+0x162/0x1f0 net/core/skbuff.c:100 RSP: ffff8801c1a6e4e8 > ---[ end trace c7cd29819a9b12ab ]--- > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, 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. > Note: all commands must start from beginning of the line in the email body. -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
