bisecting fixing commit since 14cfdbd39e316efd91ae6e403ef8211f0b022603 building syzkaller on 68660b21c27c417771037b3f1fe4aa072cfdeef9 testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0 kernel signature: 69173da2ec64d838b9293047a1ad52bc8aff0b08673487d0244d828fd9cbc48f run #0: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #1: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #2: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #3: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #4: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #5: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #6: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #7: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #8: OK run #9: OK testing current HEAD 015e94d0e37b6860e4354ce3cac56bd7c39c8992 testing commit 015e94d0e37b6860e4354ce3cac56bd7c39c8992 with gcc (GCC) 8.1.0 kernel signature: 2e6766e5fab1c6bec4b2f920a9823a8536cea4853aa57d3988bb73e84b9d42fd run #0: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #1: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #2: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #3: crashed: kernel BUG at net/sctp/sm_sideeffect.c:LINE! run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK revisions tested: 2, total time: 38m42.759815602s (build: 17m15.639646038s, test: 20m28.149871879s) the crash still happens on HEAD commit msg: Linux 4.19.146 crash: kernel BUG at net/sctp/sm_sideeffect.c:LINE! audit: type=1400 audit(1600652572.777:11): avc: denied { create } for pid=7890 comm="syz-executor.3" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=dccp_socket permissive=1 ------------[ cut here ]------------ kernel BUG at net/sctp/sm_sideeffect.c:1538! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 11289 Comm: syz-executor.3 Not tainted 4.19.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1538 [inline] RIP: 0010:sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] RIP: 0010:sctp_do_sm+0x3a42/0x5040 net/sctp/sm_sideeffect.c:1170 Code: 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 74 08 3c 03 0f 8e d0 12 00 00 f6 83 b0 02 00 00 40 0f 85 7e e5 ff ff e9 a8 e5 ff ff <0f> 0b 49 8d 7d 12 48 89 fa 48 89 f9 48 c1 ea 03 83 e1 07 42 0f b6 RSP: 0018:ffff8880a09e76c8 EFLAGS: 00010246 RAX: ffff888096330e70 RBX: ffff888096330a80 RCX: ffff8880963310b0 RDX: 1ffff11012c661ab RSI: 0000000000000012 RDI: ffff888096330d58 RBP: ffff8880a09e7980 R08: ffff8880a09e78a8 R09: ffff8880970213e8 R10: ffffed1013decb40 R11: ffff88809ef65a07 R12: 0000000000000000 R13: ffff8880a09e78e8 R14: dffffc0000000000 R15: ffff8880a09e7958 FS: 00007f1cc842a700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004ffb38 CR3: 0000000096aaf000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sctp_primitive_SHUTDOWN+0x7c/0xc0 net/sctp/primitive.c:104 sctp_close+0x354/0x750 net/sctp/socket.c:1560 inet_release+0xb4/0x1b0 net/ipv4/af_inet.c:427 inet6_release+0x46/0x60 net/ipv6/af_inet6.c:472 __sock_release+0xc2/0x290 net/socket.c:579 sock_close+0x10/0x20 net/socket.c:1140 __fput+0x249/0x7f0 fs/file_table.c:278 ____fput+0x9/0x10 fs/file_table.c:309 task_work_run+0x108/0x180 kernel/task_work.c:113 get_signal+0x13b5/0x1a30 kernel/signal.c:2399 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x114/0x200 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c8c9 Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1cc8429c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: fffffffffffffe00 RBX: 00007f1cc842a6d4 RCX: 000000000045c8c9 RDX: 000000000000006e RSI: 0000000000000084 RDI: 0000000000000004 RBP: 000000000076bf00 R08: 0000000000000020 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000ade R14: 00000000004d71b8 R15: 000000000076bf0c Modules linked in: ---[ end trace dcbfb574eacbad65 ]--- RIP: 0010:sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1538 [inline] RIP: 0010:sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] RIP: 0010:sctp_do_sm+0x3a42/0x5040 net/sctp/sm_sideeffect.c:1170 Code: 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 74 08 3c 03 0f 8e d0 12 00 00 f6 83 b0 02 00 00 40 0f 85 7e e5 ff ff e9 a8 e5 ff ff <0f> 0b 49 8d 7d 12 48 89 fa 48 89 f9 48 c1 ea 03 83 e1 07 42 0f b6 RSP: 0018:ffff8880a09e76c8 EFLAGS: 00010246 RAX: ffff888096330e70 RBX: ffff888096330a80 RCX: ffff8880963310b0 RDX: 1ffff11012c661ab RSI: 0000000000000012 RDI: ffff888096330d58 RBP: ffff8880a09e7980 R08: ffff8880a09e78a8 R09: ffff8880970213e8 R10: ffffed1013decb40 R11: ffff88809ef65a07 R12: 0000000000000000 R13: ffff8880a09e78e8 R14: dffffc0000000000 R15: ffff8880a09e7958 FS: 00007f1cc842a700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071f194 CR3: 0000000096aaf000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400