Hello,

syzbot found the following issue on:

HEAD commit: 800829388818 mm: vmscan: reduce throttling due to a failur.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=158d5fc3b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=35d2332e44a37812 dashboard link: https://syzkaller.appspot.com/bug?extid=b7db9fbc95be52cf485d compiler: arm-linux-gnueabi-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: arm

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b7db9fbc95be52cf485d@syzkaller.appspotmail.com

------------[ cut here ]------------ WARNING: CPU: 1 PID: 13058 at drivers/gpu/drm/drm_atomic_helper.c:1514 drm_atomic_helper_wait_for_vblanks.part.0+0x2ac/0x2b8 drivers/gpu/drm/drm_atomic_helper.c:1514 [CRTC:32:crtc-0] vblank wait timed out Modules linked in: Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 13058 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: ARM-Versatile Express Backtrace: [<816bd724>] (dump_backtrace) from [<816bd910>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:237) r7:81d53678 r6:82222be8 r5:60000093 r4:81d60e84 [<816bd8f8>] (show_stack) from [<816c6398>] (__dump_stack lib/dump_stack.c:88 [inline]) [<816bd8f8>] (show_stack) from [<816c6398>] (dump_stack_lvl+0x48/0x54 lib/dump_stack.c:106) [<816c6350>] (dump_stack_lvl) from [<816c63bc>] (dump_stack+0x18/0x1c lib/dump_stack.c:113) r5:00000000 r4:8243cd18 [<816c63a4>] (dump_stack) from [<816be3f0>] (panic+0x104/0x32c kernel/panic.c:232) [<816be2ec>] (panic) from [<80241f08>] (__warn+0xa4/0x134 kernel/panic.c:603) r3:8220c488 r2:00000000 r1:00000000 r0:81d53678 r7:00000009 [<80241e64>] (__warn) from [<816be6b4>] (warn_slowpath_fmt+0x9c/0xd4 kernel/panic.c:633) r7:809265bc r6:000005ea r5:81dc58c0 r4:81dc5e60 [<816be61c>] (warn_slowpath_fmt) from [<809265bc>] (drm_atomic_helper_wait_for_vblanks.part.0+0x2ac/0x2b8 drivers/gpu/drm/drm_atomic_helper.c:1514) r8:0000161b r7:00000000 r6:850c0cc0 r5:840dc050 r4:00000000 [<80926310>] (drm_atomic_helper_wait_for_vblanks.part.0) from [<80927bf4>] (drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1490 [inline]) [<80926310>] (drm_atomic_helper_wait_for_vblanks.part.0) from [<80927bf4>] (drm_atomic_helper_commit_tail+0x80/0x90 drivers/gpu/drm/drm_atomic_helper.c:1590) r10:8421c15c r9:83f4c000 r8:00000000 r7:00000168 r6:f8c64d30 r5:83f4c000 r4:850c0cc0 [<80927b74>] (drm_atomic_helper_commit_tail) from [<8092873c>] (commit_tail+0x164/0x188 drivers/gpu/drm/drm_atomic_helper.c:1667) r5:00000000 r4:850c0cc0 [<809285d8>] (commit_tail) from [<809290e8>] (drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:1884 [inline]) [<809285d8>] (commit_tail) from [<809290e8>] (drm_atomic_helper_commit+0x14c/0x170 drivers/gpu/drm/drm_atomic_helper.c:1817) r9:83f4c000 r8:850c0cec r7:00000000 r6:83f4c000 r5:00000000 r4:850c0cc0 [<80928f9c>] (drm_atomic_helper_commit) from [<80949588>] (drm_atomic_commit+0x4c/0x58 drivers/gpu/drm/drm_atomic.c:1412) r9:83f4c000 r8:840dc340 r7:00000001 r6:83f4c000 r5:850c0cc0 r4:00000000 [<8094953c>] (drm_atomic_commit) from [<80960b8c>] (drm_client_modeset_commit_atomic+0x200/0x248 drivers/gpu/drm/drm_client_modeset.c:1043) r7:00000001 r6:00000001 r5:83f4c1ac r4:850c0cc0 [<8096098c>] (drm_client_modeset_commit_atomic) from [<80960cac>] (drm_client_modeset_commit_locked+0x64/0x18c drivers/gpu/drm/drm_client_modeset.c:1146) r10:8220c44c r9:83f4c094 r8:81dcd740 r7:8411f818 r6:8411f800 r5:83f4c000 r4:83f4c000 [<80960c48>] (drm_client_modeset_commit_locked) from [<80960e00>] (drm_client_modeset_commit+0x2c/0x48 drivers/gpu/drm/drm_client_modeset.c:1172) r9:83f4c094 r8:81dcd740 r7:8411f8b4 r6:00000000 r5:83f4c000 r4:8411f800 [<80960dd4>] (drm_client_modeset_commit) from [<80930dc4>] (__drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:252 [inline]) [<80960dd4>] (drm_client_modeset_commit) from [<80930dc4>] (__drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:231 [inline]) [<80960dd4>] (drm_client_modeset_commit) from [<80930dc4>] (drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:279 [inline]) [<80960dd4>] (drm_client_modeset_commit) from [<80930dc4>] (drm_fb_helper_lastclose drivers/gpu/drm/drm_fb_helper.c:2003 [inline]) [<80960dd4>] (drm_client_modeset_commit) from [<80930dc4>] (drm_fbdev_client_restore+0x5c/0x98 drivers/gpu/drm/drm_fb_helper.c:2403) r5:823487f8 r4:8411f800 [<80930d68>] (drm_fbdev_client_restore) from [<809605e0>] (drm_client_dev_restore+0x7c/0xc8 drivers/gpu/drm/drm_client.c:226) r7:83f4c0a8 r6:83f4c000 r5:83f4c06c r4:8411f800 [<80960564>] (drm_client_dev_restore) from [<80933b00>] (drm_lastclose drivers/gpu/drm/drm_file.c:467 [inline]) [<80960564>] (drm_client_dev_restore) from [<80933b00>] (drm_release+0x130/0x150 drivers/gpu/drm/drm_file.c:498) r9:5ac3c35a r8:847bb610 r7:842190c0 r6:850c1900 r5:83f4c06c r4:83f4c000 [<809339d0>] (drm_release) from [<80487ed0>] (__fput+0x84/0x258 fs/file_table.c:280) r7:82ccce58 r6:83932ba8 r5:000a201d r4:850c1900 [<80487e4c>] (__fput) from [<80488120>] (____fput+0x10/0x14 fs/file_table.c:313) r9:5ac3c35a r8:836f8854 r7:8243d600 r6:836f8000 r5:836f8824 r4:00000000 [<80488110>] (____fput) from [<80266f04>] (task_work_run+0x8c/0xb8 kernel/task_work.c:164) [<80266e78>] (task_work_run) from [<8020bff0>] (tracehook_notify_resume include/linux/tracehook.h:189 [inline]) [<80266e78>] (task_work_run) from [<8020bff0>] (do_work_pending+0x438/0x53c arch/arm/kernel/signal.c:630) r9:5ac3c35a r8:80200244 r7:fffffe30 r6:80200244 r5:85195fb0 r4:836f8000 [<8020bbb8>] (do_work_pending) from [<80200088>] (slow_work_pending+0xc/0x20) Exception stack(0x85195fb0 to 0x85195ff8) 5fa0: 00000000 00000002 00000000 00000003 5fc0: 00000004 01d844c0 0012bf94 00000006 00000000 0012bf88 00130240 00000000 5fe0: 2ce20000 7edf8348 000291dc 00029698 80000010 00000003 r10:00000006 r9:836f8000 r8:80200244 r7:00000006 r6:0012bf94 r5:01d844c0 r4:00000004 Rebooting in 86400 seconds..

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