bisecting fixing commit since 0c88e405c97ed1828443b67891e6d4bb6e56cd4e
building syzkaller on e34b696c0d7c04dbc824dee8b5123969bbca19b7
testing commit 0c88e405c97ed1828443b67891e6d4bb6e56cd4e with gcc (GCC) 8.4.1 20210217
kernel signature: 577424b38da9a46807cf98a62e9ade18facbd0421755fe0e4b1e877975c32645
run #0: crashed: general protection fault in vgem_fence_attach_ioctl
run #1: crashed: general protection fault in vgem_fence_attach_ioctl
run #2: crashed: general protection fault in vgem_fence_attach_ioctl
run #3: crashed: KASAN: use-after-free Read in reservation_object_test_signaled_rcu
run #4: crashed: general protection fault in vgem_fence_attach_ioctl
run #5: crashed: general protection fault in vgem_fence_attach_ioctl
run #6: crashed: WARNING in mutex_destroy
run #7: crashed: general protection fault in vgem_fence_attach_ioctl
run #8: crashed: general protection fault in vgem_fence_attach_ioctl
run #9: crashed: WARNING in mutex_destroy
run #10: crashed: general protection fault in vgem_fence_attach_ioctl
run #11: crashed: WARNING in mutex_destroy
run #12: crashed: WARNING in mutex_destroy
run #13: crashed: general protection fault in vgem_fence_attach_ioctl
run #14: crashed: KASAN: use-after-free Read in reservation_object_test_signaled_rcu
run #15: crashed: general protection fault in vgem_fence_attach_ioctl
run #16: crashed: WARNING in mutex_destroy
run #17: crashed: general protection fault in vgem_fence_attach_ioctl
run #18: crashed: general protection fault in vgem_fence_attach_ioctl
run #19: crashed: general protection fault in vgem_fence_attach_ioctl
testing current HEAD 78fec1611cbf7b0bdaddfdbf174a3a2463663bff
testing commit 78fec1611cbf7b0bdaddfdbf174a3a2463663bff with gcc (GCC) 8.4.1 20210217
kernel signature: 63b580837e8cf75130ce6b9287760a5d0f7a7201b1cd9da96051743d7e730633
run #0: crashed: general protection fault in vgem_fence_attach_ioctl
run #1: crashed: WARNING in mutex_destroy
run #2: crashed: WARNING in mutex_destroy
run #3: crashed: WARNING in mutex_destroy
run #4: crashed: WARNING in mutex_destroy
run #5: crashed: KASAN: use-after-free Read in reservation_object_test_signaled_rcu
run #6: crashed: general protection fault in vgem_fence_attach_ioctl
run #7: crashed: general protection fault in vgem_fence_attach_ioctl
run #8: crashed: WARNING in mutex_destroy
run #9: crashed: general protection fault in vgem_fence_attach_ioctl
revisions tested: 2, total time: 35m16.233826604s (build: 15m54.827765091s, test: 18m57.829156864s)
the crash still happens on HEAD
commit msg: Linux 4.19.183
crash: general protection fault in vgem_fence_attach_ioctl
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 17993 Comm: syz-executor503 Not tainted 4.19.183-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:vgem_fence_attach_ioctl+0x250/0x580 drivers/gpu/drm/vgem/vgem_fence.c:184
Code: 80 3c 02 00 0f 85 01 03 00 00 4d 8b bc 24 10 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bf e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 cd 02 00 00 49 8b 87 e0 00 00 00 4c 89 f2 48 c1
RSP: 0018:ffff8881c457fa70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881db802540 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff8881c457fab0 R08: ffffed103ec84561 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d3a20540
R13: ffff8881f1bcbac0 R14: ffff8881db802544 R15: 0000000000000000
FS:  00007fd866748700(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000049b020 CR3: 00000001d630b002 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 drm_ioctl_kernel+0x1b7/0x240 drivers/gpu/drm/drm_ioctl.c:757
 drm_ioctl+0x6a9/0xae0 drivers/gpu/drm/drm_ioctl.c:857
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688
 ksys_ioctl+0x62/0x90 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44a299
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd866748308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004cb508 RCX: 000000000044a299
RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000005
RBP: 00000000004cb500 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb50c
R13: 000000000049b07c R14: 6972642f7665642f R15: 0000000000022000
Modules linked in:
---[ end trace dd2d848f6f12ebc7 ]---
RIP: 0010:vgem_fence_attach_ioctl+0x250/0x580 drivers/gpu/drm/vgem/vgem_fence.c:184
Code: 80 3c 02 00 0f 85 01 03 00 00 4d 8b bc 24 10 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bf e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 cd 02 00 00 49 8b 87 e0 00 00 00 4c 89 f2 48 c1
RSP: 0018:ffff8881c457fa70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881db802540 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff8881c457fab0 R08: ffffed103ec84561 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d3a20540
R13: ffff8881f1bcbac0 R14: ffff8881db802544 R15: 0000000000000000
FS:  00007fd866748700(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd866706718 CR3: 00000001d630b001 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400