Good day, dear maintainers, We found a bug using a modified version of syzkaller.
Kernel Branch: 7.0-rc1 Kernel Config: <https://drive.google.com/open?id=1zJHAs5GUroGFBkxAlzfDaWAd_NVPZTfJ> Unfortunately, we don't have any reproducer for this bug yet. Thank you! Best regards, Sanan Hasanov ------------[ cut here ]------------ [CRTC:35:crtc-0] vblank wait timed out WARNING: drivers/gpu/drm/drm_atomic_helper.c:1922 at drm_atomic_helper_wait_for_vblanks+0x75f/0x8e0 drivers/gpu/drm/drm_atomic_helper.c:1921, CPU#0: kworker/0:0/9 Modules linked in: CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 7.0.0-rc1 #1 PREEMPT(full) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: events drm_fb_helper_damage_work RIP: 0010:drm_atomic_helper_wait_for_vblanks+0x7ab/0x8e0 drivers/gpu/drm/drm_atomic_helper.c:1921 Code: 45 8b b6 d8 00 00 00 4c 8d 68 20 4c 89 e8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ef e8 0f fc e2 fc 49 8b 55 00 4c 89 ff 44 89 f6 <67> 48 0f b9 3a 4d 89 e5 e9 34 ff ff ff 44 89 f1 80 e1 07 80 c1 03 RSP: 0018:ffffc900001af420 EFLAGS: 00010246 RAX: 1ffff11003d97a68 RBX: dffffc0000000000 RCX: ffff8880196f5700 RDX: ffff88801f06b6a0 RSI: 0000000000000023 RDI: ffffffff8f996300 RBP: ffffc900001af548 R08: ffffffff8f8dfdb7 R09: 1ffffffff1f1bfb6 R10: dffffc0000000000 R11: fffffbfff1f1bfb7 R12: ffff8880220eb528 R13: ffff88801ecbd340 R14: 0000000000000023 R15: ffffffff8f996300 FS: 0000000000000000(0000) GS:ffff88809c136000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558b4346e5d8 CR3: 000000000dd4a000 CR4: 00000000000006f0 Call Trace: <TASK> drm_atomic_helper_commit_tail+0x302/0x530 drivers/gpu/drm/drm_atomic_helper.c:1997 commit_tail+0x2a5/0x390 drivers/gpu/drm/drm_atomic_helper.c:2074 drm_atomic_helper_commit+0xa50/0xaf0 drivers/gpu/drm/drm_atomic_helper.c:2312 drm_atomic_commit+0x25c/0x2c0 drivers/gpu/drm/drm_atomic.c:1775 drm_atomic_helper_dirtyfb+0xd7b/0xed0 drivers/gpu/drm/drm_damage_helper.c:183 drm_fbdev_shmem_helper_fb_dirty+0x175/0x310 drivers/gpu/drm/drm_fbdev_shmem.c:117 drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:248 [inline] drm_fb_helper_damage_work+0x2a2/0x730 drivers/gpu/drm/drm_fb_helper.c:274 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xae1/0x1800 kernel/workqueue.c:3358 worker_thread+0xa0f/0xf70 kernel/workqueue.c:3439 kthread+0x37d/0x470 kernel/kthread.c:467 ret_from_fork+0x507/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:245 </TASK> ---------------- Code disassembly (best guess): 0: 45 8b b6 d8 00 00 00 mov 0xd8(%r14),%r14d 7: 4c 8d 68 20 lea 0x20(%rax),%r13 b: 4c 89 e8 mov %r13,%rax e: 48 c1 e8 03 shr $0x3,%rax 12: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 16: 74 08 je 0x20 18: 4c 89 ef mov %r13,%rdi 1b: e8 0f fc e2 fc call 0xfce2fc2f 20: 49 8b 55 00 mov 0x0(%r13),%rdx 24: 4c 89 ff mov %r15,%rdi 27: 44 89 f6 mov %r14d,%esi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 4d 89 e5 mov %r12,%r13 32: e9 34 ff ff ff jmp 0xffffff6b 37: 44 89 f1 mov %r14d,%ecx 3a: 80 e1 07 and $0x7,%cl 3d: 80 c1 03 add $0x3,%cl <<<<<<<<<<<<<<< tail report >>>>>>>>>>>>>>>
