bisecting fixing commit since a03957ab0fd5d7d03b512a72ab9106a1749f556e building syzkaller on 1bfa09b9672821334a7ed926244ebc39910b84f4 testing commit a03957ab0fd5d7d03b512a72ab9106a1749f556e with gcc (GCC) 8.1.0 kernel signature: c0005d664f98002589628ba024bf58b804ffcbd8b9f164d0d3b17e3547c8c7b7 run #0: crashed: general protection fault in flex_array_get run #1: crashed: general protection fault in flex_array_get run #2: crashed: general protection fault in flex_array_get run #3: crashed: general protection fault in flex_array_get run #4: crashed: general protection fault in flex_array_get run #5: crashed: general protection fault in flex_array_get run #6: crashed: general protection fault in flex_array_get run #7: crashed: general protection fault in corrupted run #8: crashed: general protection fault in flex_array_get run #9: crashed: general protection fault in flex_array_get testing current HEAD 88d6de67e390b6093f2c11189ad022988a9e2961 testing commit 88d6de67e390b6093f2c11189ad022988a9e2961 with gcc (GCC) 8.1.0 kernel signature: 6130db4230d06758fce0fe7e1746e0ae25a2e9f84a4c8e0ce0958d2ae2e03380 run #0: crashed: general protection fault in corrupted run #1: crashed: general protection fault in flex_array_get run #2: crashed: general protection fault in flex_array_get run #3: crashed: general protection fault in flex_array_get run #4: crashed: general protection fault in flex_array_get run #5: crashed: general protection fault in flex_array_get run #6: crashed: general protection fault in flex_array_get run #7: crashed: general protection fault in flex_array_get run #8: crashed: general protection fault in flex_array_get run #9: crashed: general protection fault in flex_array_get revisions tested: 2, total time: 26m34.151346177s (build: 18m31.217513456s, test: 7m16.131516656s) the crash still happens on HEAD commit msg: Linux 4.19.99 crash: general protection fault in flex_array_get kasan: CONFIG_KASAN_INLINE enabled Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0x13 lib/fault-inject.c:149 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 7261 Comm: syz-executor.0 Not tainted 4.19.99-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:flex_array_get+0x23/0x240 lib/flex_array.c:320 Code: 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 56 41 55 41 54 53 48 89 fb 48 83 ec 10 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8d 01 00 00 44 8b 33 45 85 f6 RSP: 0018:ffff888095ba75a0 EFLAGS: 00010286 __should_failslab+0xba/0xf0 mm/failslab.c:32 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11014a38286 should_failslab+0x9/0x14 mm/slab_common.c:1558 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888095ba75d0 R08: 0000000000000000 R09: ffffed1015d44732 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc_node mm/slab.c:3304 [inline] kmem_cache_alloc_node+0x56/0x730 mm/slab.c:3647 R10: ffffed1015d44732 R11: ffff8880aea23993 R12: ffff88808c4fc840 __alloc_skb+0xa7/0x580 net/core/skbuff.c:193 R13: ffff8880768c1f84 R14: ffff8880984edf00 R15: 1ffff1101189f9f1 FS: 00007f09fd2fd700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 alloc_skb include/linux/skbuff.h:995 [inline] sctp_packet_transmit+0x26b/0x3490 net/sctp/output.c:584 CR2: 00007fe1aa075330 CR3: 000000008c56c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sctp_stream_out include/net/sctp/structs.h:1474 [inline] sctp_sched_dequeue_done+0x1d8/0x300 net/sctp/stream_sched.c:255 sctp_packet_singleton net/sctp/outqueue.c:791 [inline] sctp_outq_flush_ctrl.constprop.12+0x5f7/0xcb0 net/sctp/outqueue.c:922 __sctp_outq_teardown+0x660/0xc30 net/sctp/outqueue.c:267 sctp_outq_free+0x9/0x10 net/sctp/outqueue.c:291 sctp_association_free+0x1d5/0x711 net/sctp/associola.c:361 sctp_outq_flush+0xd0/0x22f0 net/sctp/outqueue.c:1204 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:944 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1332 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x9a2/0x53b0 net/sctp/sm_sideeffect.c:1170 sctp_outq_uncork+0x49/0x60 net/sctp/outqueue.c:776 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1328 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x3711/0x53b0 net/sctp/sm_sideeffect.c:1170 sctp_primitive_SHUTDOWN+0x7c/0xc0 net/sctp/primitive.c:104 sctp_close+0x354/0x750 net/sctp/socket.c:1545 inet_release+0xb9/0x1b0 net/ipv4/af_inet.c:427 __sock_release+0xc7/0x2a0 net/socket.c:579 sock_close+0x10/0x20 net/socket.c:1140 __fput+0x24c/0x7f0 fs/file_table.c:278 ____fput+0x9/0x10 fs/file_table.c:309 task_work_run+0x10e/0x190 kernel/task_work.c:113 get_signal+0x139f/0x1a00 kernel/signal.c:2394 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:821 sctp_assoc_bh_rcv+0x27f/0x5c0 net/sctp/associola.c:1073 sctp_inq_push+0x1aa/0x240 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x1ac/0x1280 net/sctp/input.c:356 sk_backlog_rcv include/net/sock.h:946 [inline] __release_sock+0x10c/0x360 net/core/sock.c:2339 release_sock+0x4f/0x180 net/core/sock.c:2855 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+0x419/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f09fd2fcc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 000000000001fff8 RBX: 00007f09fd2fcc90 RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f09fd2fd6d4 R13: 00000000004c5ff5 R14: 00000000004da7d8 R15: 0000000000000005 Modules linked in: ---[ end trace 578f3a13e91524cc ]--- sctp_wait_for_connect+0x22c/0x4c0 net/sctp/socket.c:8617 sctp_sendmsg_to_asoc+0x10e8/0x15d0 net/sctp/socket.c:1971 RIP: 0010:flex_array_get+0x23/0x240 lib/flex_array.c:320 Code: 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 56 41 55 41 54 53 48 89 fb 48 83 ec 10 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8d 01 00 00 44 8b 33 45 85 f6 RSP: 0018:ffff888095ba75a0 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11014a38286 sctp_sendmsg+0xd4f/0x17e0 net/sctp/socket.c:2117 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:632 ___sys_sendmsg+0x649/0x950 net/socket.c:2115 RBP: ffff888095ba75d0 R08: 0000000000000000 R09: ffffed1015d44732 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160 R10: ffffed1015d44732 R11: ffff8880aea23993 R12: ffff88808c4fc840 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3e43d77c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3e43d77c90 RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3e43d786d4 R13: ffff8880768c1f84 R14: ffff8880984edf00 R15: 1ffff1101189f9f1 R13: 00000000004c5ff5 R14: 00000000004da7d8 R15: 0000000000000005 FS: 00007f09fd2fd700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 7263 Comm: syz-executor.4 Tainted: G D 4.19.99-syzkaller #0 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0x13 lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1558 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc_trace+0x4b/0x750 mm/slab.c:3623 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] sctp_add_bind_addr+0x5f/0x320 net/sctp/bind_addr.c:159 sctp_copy_local_addr_list+0x2bb/0x400 net/sctp/protocol.c:179 sctp_copy_one_addr+0x47/0xf0 net/sctp/bind_addr.c:449 sctp_bind_addr_copy+0xe6/0x26d net/sctp/bind_addr.c:71 CR2: 00007fe1aa075330 CR3: 000000008c56c000 CR4: 00000000001406f0 sctp_assoc_set_bind_addr_from_ep+0x119/0x1c0 net/sctp/associola.c:1607 sctp_sendmsg_new_asoc+0x2ef/0xdc0 net/sctp/socket.c:1730 sctp_sendmsg+0x116e/0x17e0 net/sctp/socket.c:2090 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:632 ___sys_sendmsg+0x649/0x950 net/socket.c:2115 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400