* [syzbot] [dri?] linux-next test error: WARNING in drm_mode_config_validate
@ 2026-07-19 17:11 syzbot
2026-07-19 20:15 ` Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode syzbot
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2026-07-19 17:11 UTC (permalink / raw)
To: airlied, dri-devel, hamohammed.sa, linux-kernel, linux-next,
louis.chauvet, maarten.lankhorst, melissa.srw, mripard, sfr,
simona, syzkaller-bugs, tzimmermann
Hello,
syzbot found the following issue on:
HEAD commit: 0718283ab28b Add linux-next specific files for 20260717
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16351c32580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f6d4fd2982f9977
dashboard link: https://syzkaller.appspot.com/bug?extid=6245cb95ae707991bffa
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/83fbf4236ddb/disk-0718283a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/53d15a8f3db7/vmlinux-0718283a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d826bc7a4a27/bzImage-0718283a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6245cb95ae707991bffa@syzkaller.appspotmail.com
smbdirect: subsystem loaded
Key type cifs.spnego registered
Key type cifs.idmap registered
ntfs3: Enabled Linux POSIX ACLs support
ntfs3: Read-only LZX/Xpress compression included
jffs2: version 2.2. (NAND) (SUMMARY) © 2001-2006 Red Hat, Inc.
romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
QNX4 filesystem 0.2.3 registered.
qnx6: QNX6 filesystem 1.0.0 registered.
fuse: init (API version 7.45)
orangefs_debugfs_init: called with debug mask: :none: :0:
orangefs_init: module version upstream loaded
JFS: nTxBlock = 8192, nTxLock = 65536
SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
9p: Installing v9fs 9p2000 file system support
NILFS version 2 loaded
befs: version: 0.9.3
ocfs2: Registered cluster interface o2cb
ocfs2: Registered cluster interface user
OCFS2 User DLM kernel interface loaded
gfs2: GFS2 installed
ceph: loaded (mds proto 32)
NET: Registered PF_ALG protocol family
async_tx: api initialized (async)
Key type asymmetric registered
Asymmetric key parser 'x509' registered
Asymmetric key parser 'pkcs8' registered
Key type pkcs7_test registered
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
io scheduler mq-deadline registered
io scheduler kyber registered
io scheduler bfq registered
raid6: skipped pq benchmark and selected avx2x4
input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
ACPI: button: Power Button [PWRF]
input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
ACPI: button: Sleep Button [SLPF]
ioatdma: Intel(R) QuickData Technology Driver 5.00
N_HDLC line discipline registered with maxframe=4096
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
00:02: ttyS0 I/O:0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:03: ttyS1 I/O:0x2f8 (irq = 3, base_baud = 115200) is a 16550A
00:04: ttyS2 I/O:0x3e8 (irq = 6, base_baud = 115200) is a 16550A
00:05: ttyS3 I/O:0x2e8 (irq = 7, base_baud = 115200) is a 16550A
Non-volatile memory driver v1.3
usbcore: registered new interface driver xillyusb
ACPI: bus type drm_connector registered
[drm] Initialized vgem 1.0.0 for vgem on minor 0
------------[ cut here ]------------
[PLANE:35:plane-0] pixel format with alpha exposed but blend mode not setup
WARNING: drivers/gpu/drm/drm_mode_config.c:873 at validate_blend_mode_for_alpha_formats drivers/gpu/drm/drm_mode_config.c:872 [inline], CPU#0: swapper/0/1
WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6a/0x1e60 drivers/gpu/drm/drm_mode_config.c:938, CPU#0: swapper/0/1
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:validate_blend_mode_for_alpha_formats drivers/gpu/drm/drm_mode_config.c:872 [inline]
RIP: 0010:drm_mode_config_validate+0x1cab/0x1e60 drivers/gpu/drm/drm_mode_config.c:938
Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 4d 08 a9 fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 39 fe 3a fc 49 bd 00 00 00 00 00 fc ff df
RSP: 0000:ffffc90000067810 EFLAGS: 00010246
RAX: 1ffff11004d63408 RBX: dffffc0000000000 RCX: ffff88801daeddc0
RDX: ffff8880268100e0 RSI: 0000000000000023 RDI: ffffffff9063bf50
RBP: 0000000000000023 R08: ffff888023a4e3ab R09: 1ffff11004749c75
R10: dffffc0000000000 R11: ffffed1004749c76 R12: dffffc0000000000
R13: ffffffff9063bf50 R14: ffff888026b1a040 R15: ffff888026b1a030
FS: 0000000000000000(0000) GS:ffff888124f37000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823ffff000 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
<TASK>
drm_dev_register+0x7c/0xd80 drivers/gpu/drm/drm_drv.c:1075
vkms_create+0x40d/0x4f0 drivers/gpu/drm/vkms/vkms_drv.c:208
vkms_init+0x57/0x80 drivers/gpu/drm/vkms/vkms_drv.c:240
do_one_initcall+0x250/0x870 init/main.c:1357
do_initcall_level+0x10a/0x1a0 init/main.c:1419
do_initcalls+0x59/0xa0 init/main.c:1435
kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
kernel_init+0x22/0x1d0 init/main.c:1560
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
----------------
Code disassembly (best guess):
0: 0f 85 ae 00 00 00 jne 0xb4
6: 4d 8d 77 10 lea 0x10(%r15),%r14
a: 8b 6d 00 mov 0x0(%rbp),%ebp
d: 4c 89 f0 mov %r14,%rax
10: 48 c1 e8 03 shr $0x3,%rax
14: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1)
18: 74 08 je 0x22
1a: 4c 89 f7 mov %r14,%rdi
1d: e8 4d 08 a9 fc call 0xfca9086f
22: 49 8b 16 mov (%r14),%rdx
25: 4c 89 ef mov %r13,%rdi
28: 89 ee mov %ebp,%esi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: eb 05 jmp 0x36
31: e8 39 fe 3a fc call 0xfc3afe6f
36: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
3d: fc ff df
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 3+ messages in thread
* Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode
2026-07-19 17:11 [syzbot] [dri?] linux-next test error: WARNING in drm_mode_config_validate syzbot
@ 2026-07-19 20:15 ` syzbot
0 siblings, 0 replies; 3+ messages in thread
From: syzbot @ 2026-07-19 20:15 UTC (permalink / raw)
To: linux-kernel
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.
***
Subject: [PATCH] drm/vkms: Advertise PREMULTI blend mode
Author: michail.tatas@gmail.com
#syz test
Since we only support pre-multiplied alpha blend mode,
advertise that, otherwise validate_blend_mode_for_alpha_formats()
will throw a WARN.
Signed-off-by: Michail Tatas <michail.tatas@gmail.com>
---
drivers/gpu/drm/vkms/vkms_plane.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 68cb2a3335e6..5a875fc90dee 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -246,6 +246,12 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
DRM_COLOR_YCBCR_BT601,
DRM_COLOR_YCBCR_FULL_RANGE);
+ /* Since our composer only supports pre-multiplied alpha,
+ * advertise only the PREMULTI blend mode.
+ */
+ drm_plane_create_blend_mode_property(&plane->base,
+ BIT(DRM_MODE_BLEND_PREMULTI));
+
if (vkms_config_plane_get_default_pipeline(plane_cfg))
vkms_initialize_colorops(&plane->base);
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [syzbot] [media?] INFO: trying to register non-static key in __vb2_queue_cancel
@ 2026-07-15 3:16 syzbot
2026-07-18 13:47 ` Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode syzbot
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2026-07-15 3:16 UTC (permalink / raw)
To: linux-kernel, linux-media, m.szyprowski, mchehab, syzkaller-bugs,
tfiga
Hello,
syzbot found the following issue on:
HEAD commit: cc2b5f627e8c Add linux-next specific files for 20260714
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17fb04b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2290ccbf984c524f
dashboard link: https://syzkaller.appspot.com/bug?extid=2302c5dc59995fbb8089
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d598b9580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14500789580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6836f8efb1da/disk-cc2b5f62.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0109d3477cc7/vmlinux-cc2b5f62.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c2e49e350bbf/bzImage-cc2b5f62.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2302c5dc59995fbb8089@syzkaller.appspotmail.com
em28xx 1-1:0.132: AC97 chip type couldn't be determined
em28xx 1-1:0.132: No AC97 audio processor
usb 1-1: Decoder not found
em28xx 1-1:0.132: failed to create media graph
em28xx 1-1:0.132: V4L2 device video103 deregistered
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 1 UID: 0 PID: 5649 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Workqueue: events request_module_async
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
assign_lock_key+0x133/0x150 kernel/locking/lockdep.c:1000
register_lock_class+0xcc/0x2e0 kernel/locking/lockdep.c:1315
__lock_acquire+0xaf/0x2e40 kernel/locking/lockdep.c:5128
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5906
rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56
spin_lock include/linux/spinlock_rt.h:45 [inline]
__wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124
__vb2_queue_cancel+0x2de/0xdc0 drivers/media/common/videobuf2/videobuf2-core.c:2244
vb2_core_queue_release+0x2f/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2677
vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:956 [inline]
vb2_video_unregister_device+0x15b/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1292
em28xx_v4l2_init+0x1c60/0x3140 drivers/media/usb/em28xx/em28xx-video.c:3097
em28xx_init_extension+0x120/0x1d0 drivers/media/usb/em28xx/em28xx-core.c:1248
process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379
process_scheduled_works kernel/workqueue.c:3462 [inline]
worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543
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
</TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 5649 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Workqueue: events request_module_async
RIP: 0010:__wake_up_common kernel/sched/wait.c:104 [inline]
RIP: 0010:__wake_up_common_lock+0xd6/0x1f0 kernel/sched/wait.c:125
Code: 0f 84 d4 00 00 00 44 8b 7c 24 04 eb 13 48 ba 00 00 00 00 00 fc ff df 4c 39 ed 0f 84 ba 00 00 00 49 89 ee 48 89 e8 48 c1 e8 03 <80> 3c 10 00 74 12 4c 89 f7 e8 1c ce 93 00 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc9000595f908 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8bcbd060 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1fa1890 R12: ffff88803e181b14
R13: ffff88803e181c28 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125af2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005625301fb660 CR3: 000000003774e000 CR4: 00000000003526f0
Call Trace:
<TASK>
__vb2_queue_cancel+0x2de/0xdc0 drivers/media/common/videobuf2/videobuf2-core.c:2244
vb2_core_queue_release+0x2f/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2677
vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:956 [inline]
vb2_video_unregister_device+0x15b/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1292
em28xx_v4l2_init+0x1c60/0x3140 drivers/media/usb/em28xx/em28xx-video.c:3097
em28xx_init_extension+0x120/0x1d0 drivers/media/usb/em28xx/em28xx-core.c:1248
process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379
process_scheduled_works kernel/workqueue.c:3462 [inline]
worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543
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
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__wake_up_common kernel/sched/wait.c:104 [inline]
RIP: 0010:__wake_up_common_lock+0xd6/0x1f0 kernel/sched/wait.c:125
Code: 0f 84 d4 00 00 00 44 8b 7c 24 04 eb 13 48 ba 00 00 00 00 00 fc ff df 4c 39 ed 0f 84 ba 00 00 00 49 89 ee 48 89 e8 48 c1 e8 03 <80> 3c 10 00 74 12 4c 89 f7 e8 1c ce 93 00 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc9000595f908 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8bcbd060 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1fa1890 R12: ffff88803e181b14
R13: ffff88803e181c28 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125af2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005625301fb660 CR3: 000000003774e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 0f 84 d4 00 00 00 je 0xda
6: 44 8b 7c 24 04 mov 0x4(%rsp),%r15d
b: eb 13 jmp 0x20
d: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
14: fc ff df
17: 4c 39 ed cmp %r13,%rbp
1a: 0f 84 ba 00 00 00 je 0xda
20: 49 89 ee mov %rbp,%r14
23: 48 89 e8 mov %rbp,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) <-- trapping instruction
2e: 74 12 je 0x42
30: 4c 89 f7 mov %r14,%rdi
33: e8 1c ce 93 00 call 0x93ce54
38: 48 rex.W
39: ba 00 00 00 00 mov $0x0,%edx
3e: 00 fc add %bh,%ah
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
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.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 3+ messages in thread* Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode
2026-07-15 3:16 [syzbot] [media?] INFO: trying to register non-static key in __vb2_queue_cancel syzbot
@ 2026-07-18 13:47 ` syzbot
0 siblings, 0 replies; 3+ messages in thread
From: syzbot @ 2026-07-18 13:47 UTC (permalink / raw)
To: linux-kernel
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.
***
Subject: [PATCH] drm/vkms: Advertise PREMULTI blend mode
Author: michail.tatas@gmail.com
#syz test
Since we only support pre-multiplied alpha blend mode,
advertise that.
Signed-off-by: Michail Tatas <michail.tatas@gmail.com>
---
drivers/gpu/drm/vkms/vkms_plane.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 68cb2a3335e6..8c67511d6e8c 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -246,6 +246,13 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
DRM_COLOR_YCBCR_BT601,
DRM_COLOR_YCBCR_FULL_RANGE);
+ /*
+ * Since our composer only supports pre-multiplied alpha,
+ * advertise only the PREMULTI blend mode.
+ */
+ drm_plane_create_blend_mode_property(&plane->base,
+ BIT(DRM_MODE_BLEND_PREMULTI));
+
if (vkms_config_plane_get_default_pipeline(plane_cfg))
vkms_initialize_colorops(&plane->base);
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-07-19 20:15 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2026-07-19 17:11 [syzbot] [dri?] linux-next test error: WARNING in drm_mode_config_validate syzbot
2026-07-19 20:15 ` Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode syzbot
-- strict thread matches above, loose matches on Subject: below --
2026-07-15 3:16 [syzbot] [media?] INFO: trying to register non-static key in __vb2_queue_cancel syzbot
2026-07-18 13:47 ` Forwarded: [PATCH] drm/vkms: Advertise PREMULTI blend mode syzbot
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