FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 100, space 0, times 1 CPU: 0 UID: 0 PID: 803 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: events drm_fb_helper_damage_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x40c/0x560 lib/fault-inject.c:174 should_failslab+0xa8/0x100 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4539 [inline] slab_alloc_node mm/slub.c:4897 [inline] __kmalloc_cache_noprof+0xa8/0x660 mm/slub.c:5485 _kmalloc_noprof include/linux/slab.h:988 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] drm_atomic_commit_alloc+0xa9/0x100 drivers/gpu/drm/drm_atomic.c:178 drm_atomic_helper_dirtyfb+0x129/0xfd0 drivers/gpu/drm/drm_damage_helper.c:128 drm_fbdev_shmem_helper_fb_dirty+0x160/0x310 drivers/gpu/drm/drm_fbdev_shmem.c:117 drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:339 [inline] drm_fb_helper_damage_work+0x84c/0xf20 drivers/gpu/drm/drm_fb_helper.c:365 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ------------[ cut here ]------------ virtio-pci 0000:00:01.0: [drm] Dirty helper failed: ret=-12 WARNING: drivers/gpu/drm/drm_fbdev_shmem.c:118 at drm_fbdev_shmem_helper_fb_dirty+0x1e1/0x310 drivers/gpu/drm/drm_fbdev_shmem.c:118, CPU#0: kworker/0:2/803 Modules linked in: CPU: 0 UID: 0 PID: 803 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: events drm_fb_helper_damage_work RIP: 0010:drm_fbdev_shmem_helper_fb_dirty+0x288/0x310 drivers/gpu/drm/drm_fbdev_shmem.c:118 Code: 35 fc 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 5a 5a a4 fc 4d 8b 27 48 89 df 4c 89 f6 4c 89 e2 8b 5c 24 04 89 d9 <67> 48 0f b9 3a 89 d8 e9 f7 fe ff ff 89 d9 80 e1 07 fe c1 38 c1 0f RSP: 0018:ffffc90003e3f8b8 EFLAGS: 00010246 RAX: 1ffff11003f1001a RBX: 00000000fffffff4 RCX: 00000000fffffff4 RDX: ffff88801f645de0 RSI: ffffffff8c57c700 RDI: ffffffff90638de0 RBP: ffff88801d36e008 R08: 0000000000000dc0 R09: 00000000ffffffff R10: dffffc0000000000 R11: fffffbfff1d94963 R12: ffff88801f645de0 R13: dffffc0000000000 R14: ffffffff8c57c700 R15: ffff88801f8800d0 FS: 0000000000000000(0000) GS:ffff88808c549000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa92d1afe70 CR3: 0000000012d44000 CR4: 0000000000352ef0 Call Trace: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:339 [inline] drm_fb_helper_damage_work+0x84c/0xf20 drivers/gpu/drm/drm_fb_helper.c:365 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 35 fc 4c 89 f8 xor $0xf8894cfc,%eax 5: 48 c1 e8 03 shr $0x3,%rax 9: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) e: 74 08 je 0x18 10: 4c 89 ff mov %r15,%rdi 13: e8 5a 5a a4 fc call 0xfca45a72 18: 4d 8b 27 mov (%r15),%r12 1b: 48 89 df mov %rbx,%rdi 1e: 4c 89 f6 mov %r14,%rsi 21: 4c 89 e2 mov %r12,%rdx 24: 8b 5c 24 04 mov 0x4(%rsp),%ebx 28: 89 d9 mov %ebx,%ecx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 89 d8 mov %ebx,%eax 31: e9 f7 fe ff ff jmp 0xffffff2d 36: 89 d9 mov %ebx,%ecx 38: 80 e1 07 and $0x7,%cl 3b: fe c1 inc %cl 3d: 38 c1 cmp %al,%cl 3f: 0f .byte 0xf