bisecting fixing commit since a03957ab0fd5d7d03b512a72ab9106a1749f556e building syzkaller on 1bfa09b9672821334a7ed926244ebc39910b84f4 testing commit a03957ab0fd5d7d03b512a72ab9106a1749f556e with gcc (GCC) 8.4.1 20210217 kernel signature: e5aa2ccf578d238d3861c703c5693afbe51d8ca42c38a91edff88e8df294a4c1 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 corrupted 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 run #10: crashed: general protection fault in flex_array_get run #11: crashed: general protection fault in flex_array_get run #12: crashed: general protection fault in flex_array_get run #13: crashed: general protection fault in flex_array_get run #14: crashed: general protection fault in flex_array_get run #15: crashed: general protection fault in flex_array_get run #16: crashed: general protection fault in flex_array_get run #17: crashed: general protection fault in flex_array_get run #18: crashed: general protection fault in flex_array_get run #19: crashed: general protection fault in flex_array_get testing current HEAD 78fec1611cbf7b0bdaddfdbf174a3a2463663bff testing commit 78fec1611cbf7b0bdaddfdbf174a3a2463663bff with gcc (GCC) 8.4.1 20210217 kernel signature: 5278190777fb6f411931fcfc671759b9d29c2b2efed418b751ac3b974237017e all runs: crashed: general protection fault in flex_array_get revisions tested: 2, total time: 22m48.156751306s (build: 15m17.747070197s, test: 6m49.057465712s) the crash still happens on HEAD commit msg: Linux 4.19.183 crash: general protection fault in flex_array_get radix_tree_node_alloc.constprop.19+0x4a/0x330 lib/radix-tree.c:421 idr_get_free+0x4f2/0xa30 lib/radix-tree.c:2158 idr_alloc_u32+0x146/0x360 lib/idr.c:49 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN idr_alloc_cyclic+0xeb/0x1e0 lib/idr.c:128 CPU: 0 PID: 6632 Comm: syz-executor.4 Not tainted 4.19.183-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:flex_array_get+0x23/0x250 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 86 01 00 00 44 8b 2b 45 85 ed RSP: 0018:ffff8881f57b75a8 EFLAGS: 00010282 sctp_assoc_set_id+0x7a/0x180 net/sctp/associola.c:1657 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1103bdb4006 sctp_process_init+0x205b/0x2d50 net/sctp/sm_make_chunk.c:2468 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8881f57b75d8 R08: ffff8881f57b7908 R09: ffffed103ed04732 R10: ffffed103ed04732 R11: ffff8881f6823993 R12: ffff8881d32740c0 R13: ffff8881c6a01304 R14: ffff8881e3882880 R15: 1ffff1103a64e901 FS: 00007f99fa819700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8a1c2bb028 CR3: 00000001dab2c004 CR4: 00000000001606f0 sctp_cmd_process_init net/sctp/sm_sideeffect.c:682 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1391 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x9f6/0x4e60 net/sctp/sm_sideeffect.c:1170 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_outq_teardown+0x660/0xc30 net/sctp/outqueue.c:268 sctp_outq_free+0x9/0x10 net/sctp/outqueue.c:292 sctp_association_free+0x1d5/0x720 net/sctp/associola.c:361 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+0x989/0x4e60 net/sctp/sm_sideeffect.c:1170 sctp_assoc_bh_rcv+0x27f/0x5c0 net/sctp/associola.c:1073 sctp_inq_push+0x1aa/0x240 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x1ab/0x13b0 net/sctp/input.c:356 sk_backlog_rcv include/net/sock.h:950 [inline] __release_sock+0x10c/0x360 net/core/sock.c:2344 release_sock+0x4f/0x180 net/core/sock.c:2881 sctp_wait_for_connect+0x22c/0x4c0 net/sctp/socket.c:8634 sctp_sendmsg_to_asoc+0x16c5/0x1f70 net/sctp/socket.c:1989 sctp_primitive_SHUTDOWN+0x7c/0xc0 net/sctp/primitive.c:104 sctp_close+0x354/0x750 net/sctp/socket.c:1560 sctp_sendmsg+0xf24/0x1670 net/sctp/socket.c:2135 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 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 task_work_run+0x10e/0x190 kernel/task_work.c:113 get_signal+0x13ad/0x19e0 kernel/signal.c:2400 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:799 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 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: 0033:0x4605f9 __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 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 RSP: 002b:00007f99fa819198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e entry_SYSCALL_64_after_hwframe+0x49/0xbe RAX: 000000000001fff8 RBX: 000000000052bf00 RCX: 00000000004605f9 RIP: 0033:0x4605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 RSP: 002b:00007fbd6b5ea198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 00000000004605f9 R13: 0000000000000003 R14: 00000000004b178a R15: 00007f99fa8196bc RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 Modules linked in: RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 ---[ end trace a7e2df06548a3bb7 ]--- R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000003 R14: 00000000004b178a R15: 00007fbd6b5ea6bc RIP: 0010:flex_array_get+0x23/0x250 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 86 01 00 00 44 8b 2b 45 85 ed RSP: 0018:ffff8881f57b75a8 EFLAGS: 00010282 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1103bdb4006 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8881f57b75d8 R08: ffff8881f57b7908 R09: ffffed103ed04732 R10: ffffed103ed04732 R11: ffff8881f6823993 R12: ffff8881d32740c0 R13: ffff8881c6a01304 R14: ffff8881e3882880 R15: 1ffff1103a64e901 FS: 00007f99fa819700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557c05d10670 CR3: 00000001dab2c001 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400