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 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 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 corrupted 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 1e986fe9ad15b8406034c504afc5ae76f0a8e852 testing commit 1e986fe9ad15b8406034c504afc5ae76f0a8e852 with gcc (GCC) 8.4.1 20210217 kernel signature: 69a46e5870afc1271bcfef1e45670d2850334d42b35cbc63d4cf400f6636b66c all runs: crashed: general protection fault in flex_array_get revisions tested: 2, total time: 31m34.559026679s (build: 23m18.566813643s, test: 7m13.492888258s) the crash still happens on HEAD commit msg: Linux 4.19.191 crash: general protection fault in flex_array_get kasan: GPF could be caused by NULL-ptr deref or user memory access __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x20 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x47/0x730 mm/slab.c:3557 general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 7022 Comm: syz-executor.2 Not tainted 4.19.191-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kmem_cache_zalloc include/linux/slab.h:699 [inline] sctp_chunkify+0x46/0x270 net/sctp/sm_make_chunk.c:1349 RIP: 0010:flex_array_get+0x23/0x250 lib/flex_array.c:320 _sctp_make_chunk+0x128/0x260 net/sctp/sm_make_chunk.c:1422 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 sctp_make_control net/sctp/sm_make_chunk.c:1458 [inline] sctp_make_cookie_echo+0x85/0x160 net/sctp/sm_make_chunk.c:591 RSP: 0018:ffff8881e18df5a8 EFLAGS: 00010282 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1397 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x27cb/0x4e60 net/sctp/sm_sideeffect.c:1170 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1103cde4a56 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8881e18df5d8 R08: ffff8881e18df908 R09: ffffed103ed04732 R10: ffffed103ed04732 R11: ffff8881f6823993 R12: ffff8881e8a52040 R13: ffff8881c4a81e04 R14: ffff8881f45adc00 R15: 1ffff1103d14a4f1 FS: 00007ff63112e700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564a6ff950e8 CR3: 00000001f53db005 CR4: 00000000001606f0 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_assoc_bh_rcv+0x27f/0x5c0 net/sctp/associola.c:1073 __sctp_outq_teardown+0x660/0xc30 net/sctp/outqueue.c:268 sctp_inq_push+0x1aa/0x240 net/sctp/inqueue.c:95 sctp_backlog_rcv+0x1ab/0x13b0 net/sctp/input.c:356 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 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:8635 sctp_primitive_SHUTDOWN+0x7c/0xc0 net/sctp/primitive.c:104 sctp_sendmsg_to_asoc+0x16c5/0x1f70 net/sctp/socket.c:2003 sctp_close+0x354/0x750 net/sctp/socket.c:1574 inet_release+0xb9/0x1b0 net/ipv4/af_inet.c:427 __sock_release+0xc7/0x2a0 net/socket.c:579 sctp_sendmsg+0xf24/0x1670 net/sctp/socket.c:2149 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+0x13ad/0x19e0 kernel/signal.c:2400 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:799 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:632 ___sys_sendmsg+0x649/0x950 net/socket.c:2115 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 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 RIP: 0033:0x4605f9 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 RSP: 002b:00007ff63112e198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 000000000001fff8 RBX: 000000000052bf00 RCX: 00000000004605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 __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 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 R13: 0000000000000003 R14: 00000000004b178a R15: 00007ff63112e6bc entry_SYSCALL_64_after_hwframe+0x49/0xbe Modules linked in: RIP: 0033:0x4605f9 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 RSP: 002b:00007f2fb659f198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 00000000004605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000003 R14: 00000000004b178a R15: 00007f2fb659f6bc CPU: 0 PID: 7045 Comm: syz-executor.3 Tainted: G D 4.19.191-syzkaller #0 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+0x123/0x171 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0xa lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x20 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x47/0x730 mm/slab.c:3557 kmem_cache_zalloc include/linux/slab.h:699 [inline] fill_pool lib/debugobjects.c:134 [inline] __debug_object_init+0x7dc/0xd70 lib/debugobjects.c:379 debug_object_init+0x16/0x20 lib/debugobjects.c:431 debug_timer_init kernel/time/timer.c:713 [inline] debug_init kernel/time/timer.c:766 [inline] init_timer_key+0x2e/0x270 kernel/time/timer.c:815 sctp_association_init net/sctp/associola.c:153 [inline] sctp_association_new+0x9fd/0x1ef0 net/sctp/associola.c:317 sctp_make_temp_asoc+0x8b/0x1a0 net/sctp/sm_make_chunk.c:1606 sctp_sf_do_unexpected_init net/sctp/sm_statefuns.c:1554 [inline] sctp_sf_do_unexpected_init.isra.36+0x66c/0x1400 net/sctp/sm_statefuns.c:1466 sctp_sf_do_5_2_1_siminit+0xf/0x20 net/sctp/sm_statefuns.c:1695 sctp_do_sm+0x112/0x4e60 net/sctp/sm_sideeffect.c:1167 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:8635 sctp_sendmsg_to_asoc+0x16c5/0x1f70 net/sctp/socket.c:2003 sctp_sendmsg+0xf24/0x1670 net/sctp/socket.c:2149 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 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 __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 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4605f9 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 RSP: 002b:00007f957fd7a198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 00000000004605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000003 R14: 00000000004b178a R15: 00007f957fd7a6bc ---[ end trace 727b5d3f2f0c48f2 ]--- CPU: 1 PID: 7044 Comm: syz-executor.0 Tainted: G D 4.19.191-syzkaller #0 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+0x123/0x171 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0xa lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x20 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x47/0x730 mm/slab.c:3557 kmem_cache_zalloc include/linux/slab.h:699 [inline] fill_pool lib/debugobjects.c:134 [inline] __debug_object_init+0x7dc/0xd70 lib/debugobjects.c:379 debug_object_init+0x16/0x20 lib/debugobjects.c:431 debug_timer_init kernel/time/timer.c:713 [inline] debug_init kernel/time/timer.c:766 [inline] init_timer_key+0x2e/0x270 kernel/time/timer.c:815 sctp_association_init net/sctp/associola.c:153 [inline] sctp_association_new+0x9fd/0x1ef0 net/sctp/associola.c:317 sctp_make_temp_asoc+0x8b/0x1a0 net/sctp/sm_make_chunk.c:1606 sctp_sf_do_unexpected_init net/sctp/sm_statefuns.c:1554 [inline] sctp_sf_do_unexpected_init.isra.36+0x66c/0x1400 net/sctp/sm_statefuns.c:1466 sctp_sf_do_5_2_1_siminit+0xf/0x20 net/sctp/sm_statefuns.c:1695 sctp_do_sm+0x112/0x4e60 net/sctp/sm_sideeffect.c:1167 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:8635 sctp_sendmsg_to_asoc+0x16c5/0x1f70 net/sctp/socket.c:2003 sctp_sendmsg+0xf24/0x1670 net/sctp/socket.c:2149 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 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 __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 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4605f9 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 RSP: 002b:00007f7363bf3198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 00000000004605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000003 R14: 00000000004b178a R15: 00007f7363bf36bc CPU: 0 PID: 7036 Comm: syz-executor.5 Tainted: G D 4.19.191-syzkaller #0 RIP: 0010:flex_array_get+0x23/0x250 lib/flex_array.c:320 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+0x123/0x171 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0xa lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x20 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x47/0x730 mm/slab.c:3557 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 kmem_cache_zalloc include/linux/slab.h:699 [inline] fill_pool lib/debugobjects.c:134 [inline] __debug_object_init+0x7dc/0xd70 lib/debugobjects.c:379 debug_object_init+0x16/0x20 lib/debugobjects.c:431 debug_timer_init kernel/time/timer.c:713 [inline] debug_init kernel/time/timer.c:766 [inline] init_timer_key+0x2e/0x270 kernel/time/timer.c:815 sctp_association_init net/sctp/associola.c:153 [inline] sctp_association_new+0x9fd/0x1ef0 net/sctp/associola.c:317 sctp_make_temp_asoc+0x8b/0x1a0 net/sctp/sm_make_chunk.c:1606 sctp_sf_do_unexpected_init net/sctp/sm_statefuns.c:1554 [inline] sctp_sf_do_unexpected_init.isra.36+0x66c/0x1400 net/sctp/sm_statefuns.c:1466 sctp_sf_do_5_2_1_siminit+0xf/0x20 net/sctp/sm_statefuns.c:1695 sctp_do_sm+0x112/0x4e60 net/sctp/sm_sideeffect.c:1167 RSP: 0018:ffff8881e18df5a8 EFLAGS: 00010282 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1103cde4a56 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 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 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:8635 RBP: ffff8881e18df5d8 R08: ffff8881e18df908 R09: ffffed103ed04732 sctp_sendmsg_to_asoc+0x16c5/0x1f70 net/sctp/socket.c:2003 R10: ffffed103ed04732 R11: ffff8881f6823993 R12: ffff8881e8a52040 sctp_sendmsg+0xf24/0x1670 net/sctp/socket.c:2149 R13: ffff8881c4a81e04 R14: ffff8881f45adc00 R15: 1ffff1103d14a4f1 inet_sendmsg+0x10d/0x450 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:632 ___sys_sendmsg+0x649/0x950 net/socket.c:2115 FS: 00007ff63112e700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 __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 do_syscall_64+0xd6/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe CR2: 00007f034402c208 CR3: 00000001f53db005 CR4: 00000000001606e0 RIP: 0033:0x4605f9 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 RSP: 002b:00007f572ab09198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 00000000004605f9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000003 R14: 00000000004b178a R15: 00007f572ab096bc FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 CPU: 0 PID: 7052 Comm: syz-executor.1 Tainted: G D 4.19.191-syzkaller #0