bisecting fixing commit since 830a059cbba6832c11fefc0894c7ec7a27f75734
building syzkaller on 6a81331a1d4c744da9204d02ec88d558f7eea9c9
testing commit 830a059cbba6832c11fefc0894c7ec7a27f75734 with gcc (GCC) 8.4.1 20210217
kernel signature: d2a4e24df603f578da7df17efa7911fe25c83ced21a318df89d6fd75589e9d1a
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: general protection fault in vgem_fence_attach_ioctl
run #5: crashed: WARNING in mutex_destroy
run #6: crashed: general protection fault in vgem_fence_attach_ioctl
run #7: crashed: WARNING in mutex_destroy
run #8: crashed: general protection fault in vgem_fence_attach_ioctl
run #9: crashed: general protection fault in vgem_fence_attach_ioctl
run #10: crashed: general protection fault in vgem_fence_attach_ioctl
run #11: crashed: WARNING in mutex_destroy
run #12: crashed: general protection fault in vgem_fence_attach_ioctl
run #13: crashed: general protection fault in vgem_fence_attach_ioctl
run #14: crashed: general protection fault in vgem_fence_attach_ioctl
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 1e986fe9ad15b8406034c504afc5ae76f0a8e852
testing commit 1e986fe9ad15b8406034c504afc5ae76f0a8e852 with gcc (GCC) 8.4.1 20210217
kernel signature: 192bb15131b87186156bc90ad2baae353301704a33ff96c1db863583a2f87dd9
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: WARNING in mutex_destroy
run #4: crashed: WARNING in mutex_destroy
run #5: crashed: general protection fault in vgem_fence_attach_ioctl
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: general protection fault in vgem_fence_attach_ioctl
run #9: crashed: general protection fault in vgem_fence_attach_ioctl
revisions tested: 2, total time: 28m44.325042351s (build: 21m17.296371087s, test: 6m55.328901384s)
the crash still happens on HEAD
commit msg: Linux 4.19.191
crash: general protection fault in vgem_fence_attach_ioctl
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
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: 1 PID: 10024 Comm: syz-executor.4 Not tainted 4.19.191-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:ffff888093a97a70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809be2c080 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff888093a97ab0 R08: ffffed1017464561 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a2c9cc80
R13: ffff8880b3d68140 R14: ffff88809be2c084 R15: 0000000000000000
FS:  00007f68dae10700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5e73658d58 CR3: 00000000b42de000 CR4: 00000000001406e0
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: 0033:0x466459
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:00007f68dae10188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000003
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fffcbea9f1f R14: 00007f68dae10300 R15: 0000000000022000
Modules linked in:
Bluetooth: hci5: command 0x0419 tx timeout
Bluetooth: hci0: command 0x0419 tx timeout
Bluetooth: hci2: command 0x0419 tx timeout
Bluetooth: hci1: command 0x0419 tx timeout
Bluetooth: hci3: command 0x0419 tx timeout
Bluetooth: hci4: command 0x0419 tx timeout
---[ end trace d4c78fec7d3da1a3 ]---
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:ffff888093a97a70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809be2c080 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff888093a97ab0 R08: ffffed1017464561 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a2c9cc80
R13: ffff8880b3d68140 R14: ffff88809be2c084 R15: 0000000000000000
FS:  00007f68dae10700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005619f3fcc160 CR3: 00000000b42de000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400