Hello, syzbot found the following crash on: HEAD commit: 5076190d mm: slub: be more careful about the double cmpxch.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14d2a61de00000 kernel config: https://syzkaller.appspot.com/x/.config?x=9f894bd92023de02 dashboard link: https://syzkaller.appspot.com/bug?extid=3950016bd95c2ca0377b compiler: gcc (GCC) 9.0.0 20181231 (experimental) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1162bbe3e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13c93b45e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+3950016bd95c2ca0377b@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000017: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf] CPU: 0 PID: 10161 Comm: syz-executor044 Not tainted 5.6.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sctp_ulpevent_nofity_peer_addr_change+0xed/0xa30 net/sctp/ulpevent.c:347 Code: 03 80 3c 02 00 0f 85 19 08 00 00 48 8b ab a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bd bc 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 70 RSP: 0018:ffffc900022a7308 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888096004150 RCX: 0000000000000000 RDX: 0000000000000017 RSI: 0000000000000000 RDI: 00000000000000bc RBP: 0000000000000000 R08: ffff88809419a500 R09: ffffc900022a7358 R10: fffff52000454e7a R11: ffffc900022a73d7 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888096004150 FS: 0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:000000000935d840 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000093589000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sctp_assoc_set_primary+0x6c/0x300 net/sctp/associola.c:435 sctp_assoc_rm_peer+0x77c/0xa40 net/sctp/associola.c:508 sctp_assoc_update+0x50a/0xe30 net/sctp/associola.c:1116 sctp_cmd_assoc_update net/sctp/sm_sideeffect.c:836 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1305 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] sctp_do_sm+0x1c57/0x4ed0 net/sctp/sm_sideeffect.c:1156 sctp_assoc_bh_rcv+0x386/0x6d0 net/sctp/associola.c:1044 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x1f3/0x1290 net/sctp/input.c:344 sk_backlog_rcv include/net/sock.h:963 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2440 release_sock+0x54/0x1b0 net/core/sock.c:2956 sctp_wait_for_connect+0x308/0x530 net/sctp/socket.c:9280 __sctp_connect+0x9d2/0xc70 net/sctp/socket.c:1225 __sctp_setsockopt_connectx+0x127/0x180 net/sctp/socket.c:1321 sctp_setsockopt_connectx net/sctp/socket.c:1353 [inline] sctp_setsockopt net/sctp/socket.c:4698 [inline] sctp_setsockopt+0x15a1/0x7090 net/sctp/socket.c:4655 compat_sock_common_setsockopt+0xf6/0x120 net/core/sock.c:3165 __compat_sys_setsockopt+0x15d/0x310 net/compat.c:384 __do_compat_sys_setsockopt net/compat.c:397 [inline] __se_compat_sys_setsockopt net/compat.c:394 [inline] __ia32_compat_sys_setsockopt+0xb9/0x150 net/compat.c:394 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Modules linked in: ---[ end trace a970df05c462f077 ]--- RIP: 0010:sctp_ulpevent_nofity_peer_addr_change+0xed/0xa30 net/sctp/ulpevent.c:347 Code: 03 80 3c 02 00 0f 85 19 08 00 00 48 8b ab a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bd bc 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 70 RSP: 0018:ffffc900022a7308 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888096004150 RCX: 0000000000000000 RDX: 0000000000000017 RSI: 0000000000000000 RDI: 00000000000000bc RBP: 0000000000000000 R08: ffff88809419a500 R09: ffffc900022a7358 R10: fffff52000454e7a R11: ffffc900022a73d7 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888096004150 FS: 0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:000000000935d840 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000093589000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
