bisecting fixing commit since f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a
building syzkaller on d5a3ae1f760e7cb2cd5a721d9645ae22eae114fe
testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a with gcc (GCC) 8.1.0
kernel signature: 0fc7eafb4db5679fb98ff74dedd84f02167b649e0a2a026d24c06ff5849aaaf1
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: general protection fault in vgem_fence_attach_ioctl
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: KASAN: use-after-free Read in reservation_object_test_signaled_rcu
run #9: crashed: WARNING in mutex_destroy
testing current HEAD 675cc038067f0e530471c56a7442935f84669d95
testing commit 675cc038067f0e530471c56a7442935f84669d95 with gcc (GCC) 8.1.0
kernel signature: 700929dfb312c34b99b089596deeba001df90808659fedd14fdacafe3822376a
run #0: crashed: WARNING in mutex_destroy
run #1: crashed: general protection fault in vgem_fence_attach_ioctl
run #2: crashed: WARNING in mutex_destroy
run #3: crashed: general protection fault in vgem_fence_attach_ioctl
run #4: crashed: general protection fault in vgem_fence_attach_ioctl
run #5: crashed: WARNING in mutex_destroy
run #6: crashed: WARNING in mutex_destroy
run #7: crashed: WARNING in mutex_destroy
run #8: crashed: general protection fault in vgem_fence_attach_ioctl
run #9: OK
revisions tested: 2, total time: 31m8.769400036s (build: 19m11.706806246s, test: 11m6.417504997s)
the crash still happens on HEAD
commit msg: Linux 4.19.167
crash: general protection fault in vgem_fence_attach_ioctl
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: 17728 Comm: syz-executor.2 Not tainted 4.19.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:vgem_fence_attach_ioctl+0x24f/0x580 drivers/gpu/drm/vgem/vgem_fence.c:184
Code: 03 80 3c 02 00 0f 85 01 03 00 00 4d 8b bd 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 ce 02 00 00 49 8b 87 e0 00 00 00 4c 89 f2 48 c1
RSP: 0018:ffff8881c622fa70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881d6709a80 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff8881c622fab0 R08: ffffed103ed04749 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d4de95c0
R13: ffff8881f3ed8d00 R14: ffff8881d6709a84 R15: 0000000000000000
FS:  00007f8578fb1700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f528b310db8 CR3: 00000001f3064001 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: 0033:0x45d5b9
Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8578fb0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000c4c0 RCX: 000000000045d5b9
RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000003
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffd32a6c15f R14: 00007f8578fb19c0 R15: 000000000118cfec
Modules linked in:
---[ end trace f20f46489cb27b32 ]---
RIP: 0010:vgem_fence_attach_ioctl+0x24f/0x580 drivers/gpu/drm/vgem/vgem_fence.c:184
Code: 03 80 3c 02 00 0f 85 01 03 00 00 4d 8b bd 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 ce 02 00 00 49 8b 87 e0 00 00 00 4c 89 f2 48 c1
RSP: 0018:ffff8881c622fa70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881d6709a80 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff8881c622fab0 R08: ffffed103ed04749 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d4de95c0
R13: ffff8881f3ed8d00 R14: ffff8881d6709a84 R15: 0000000000000000
FS:  00007f8578fb1700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000746918 CR3: 00000001f3064001 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400