syzbot has found a reproducer for the following issue on: HEAD commit: d358e5254674 Merge tag 'for-6.19/dm-changes' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13c2a61a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=73d2ed7b46aaccf3 dashboard link: https://syzkaller.appspot.com/bug?extid=fcede535e7eb57cf5b43 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=145d51c2580000
Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-d358e525.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c0c4d1b8a322/vmlinux-d358e525.xz kernel image: https://storage.googleapis.com/syzbot-assets/2cdf67cb5df2/bzImage-d358e525.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] ------------[ cut here ]------------ [CRTC:37:crtc-0] vblank wait timed out WARNING: drivers/gpu/drm/drm_atomic_helper.c:1844 at 0x0, CPU#3: syz.0.33/6143 Modules linked in: CPU: 3 UID: 0 PID: 6143 Comm: syz.0.33 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:drm_atomic_helper_wait_for_vblanks.part.0+0x766/0x8c0 drivers/gpu/drm/drm_atomic_helper.c:1844 Code: 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 04 01 84 c0 74 08 3c 03 0f 8e 3f 01 00 00 48 8d 3d d0 d5 3a 0b 8b b5 d8 00 00 00 <67> 48 0f b9 3a e9 ed fc ff ff e8 1b 27 67 fc e9 81 fe ff ff e8 a1 RSP: 0018:ffffc90003fc77b0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff11020b60023 RDX: ffff8881037eb860 RSI: 0000000000000025 RDI: ffffffff90929260 RBP: ffff888105b00040 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888028f5d4b0 R12: dffffc0000000000 R13: ffff888024b40e00 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555589c49500(0000) GS:ffff8880d6bfd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6e38fc1f98 CR3: 00000000380b2000 CR4: 0000000000352ef0 Call Trace: <TASK> drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1818 [inline] drm_atomic_helper_commit_tail+0xaa/0xd0 drivers/gpu/drm/drm_atomic_helper.c:1920 commit_tail+0x334/0x410 drivers/gpu/drm/drm_atomic_helper.c:1997 drm_atomic_helper_commit+0x300/0x380 drivers/gpu/drm/drm_atomic_helper.c:2235 drm_atomic_commit+0x234/0x300 drivers/gpu/drm/drm_atomic.c:1743 drm_client_modeset_commit_atomic+0x69d/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1103 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1206 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1232 __drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:235 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:266 [inline] drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:266 drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45 drm_client_dev_restore+0x200/0x2a0 drivers/gpu/drm/drm_client_event.c:118 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline] drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e3818f7c9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff40d56468 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000010de4 RCX: 00007f6e3818f7c9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f6e383e7da0 R08: 0000000000000001 R09: 0000000540d5675f R10: 0000001b2d720000 R11: 0000000000000246 R12: 00007f6e383e5fac R13: 00007f6e383e5fa0 R14: ffffffffffffffff R15: 00007fff40d56580 </TASK> ---------------- Code disassembly (best guess), 5 bytes skipped: 0: df 48 89 fisttps -0x77(%rax) 3: f9 stc 4: 48 c1 e9 03 shr $0x3,%rcx 8: 0f b6 04 01 movzbl (%rcx,%rax,1),%eax c: 84 c0 test %al,%al e: 74 08 je 0x18 10: 3c 03 cmp $0x3,%al 12: 0f 8e 3f 01 00 00 jle 0x157 18: 48 8d 3d d0 d5 3a 0b lea 0xb3ad5d0(%rip),%rdi # 0xb3ad5ef 1f: 8b b5 d8 00 00 00 mov 0xd8(%rbp),%esi * 25: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2a: e9 ed fc ff ff jmp 0xfffffd1c 2f: e8 1b 27 67 fc call 0xfc67274f 34: e9 81 fe ff ff jmp 0xfffffeba 39: e8 .byte 0xe8 3a: a1 .byte 0xa1 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
