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From: syzbot <syzbot+caaca441bae2799984d3@syzkaller.appspotmail.com>
To: hverkuil@kernel.org, linux-kernel@vger.kernel.org,
	 linux-media@vger.kernel.org, mchehab@kernel.org,
	 syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [media?] general protection fault in vivid_probe
Date: Wed, 26 Aug 2026 02:43:30 -0700	[thread overview]
Message-ID: <6a8eb542.27659fcc.2ceef7.0000.GAE@google.com> (raw)
In-Reply-To: <6a890fa1.91706f20.16b6e3.02af.GAE@google.com>

syzbot has found a reproducer for the following issue on:

HEAD commit:    818bebeb63dd drm/xe: Don't hand out the flat CCS storage a..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1498d979580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ccca94d2c01b9e78
dashboard link: https://syzkaller.appspot.com/bug?extid=caaca441bae2799984d3
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15551625580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+caaca441bae2799984d3@syzkaller.appspotmail.com

cec: vivid-003-vid-cap0: kthread_run() failed
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000be7: 0000 [#1] SMP KASAN NOPTI
KASAN: probably user-memory-access in range [0x0000000000005f38-0x0000000000005f3f]
CPU: 2 UID: 0 PID: 6367 Comm: syz.1.18 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
RIP: 0010:vivid_probe+0x579/0x10d0 drivers/media/test-drivers/vivid/vivid-core.c:2119
Code: 3c 28 00 0f 85 36 0a 00 00 48 8b 44 24 10 48 8b 2c c5 c0 09 c8 9b 48 8d bd 39 5f 00 00 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 2c 0a 00 00 0f b6 9d 39 5f
RSP: 0018:ffffc900036ef948 EFLAGS: 00010202
RAX: 0000000000000be7 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff886a5335 RDI: 0000000000005f39
RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000002
R10: 0000000000000003 R11: dffffc0000000000 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000004 R15: 0000000000000004
FS:  00007f751a8316c0(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561c82d2e620 CR3: 0000000059c7e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1507
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868
 device_driver_attach+0xd1/0x220 drivers/base/dd.c:1203
 bind_store+0xf4/0x190 drivers/base/bus.c:267
 drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6af/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f751999e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f751a831028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7519c26090 RCX: 00007f751999e0d9
RDX: 0000000000000006 RSI: 0000200000000300 RDI: 0000000000000005
RBP: 00007f7519a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7519c26128 R14: 00007f7519c26090 R15: 00007ffe76265b18
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:vivid_probe+0x579/0x10d0 drivers/media/test-drivers/vivid/vivid-core.c:2119
Code: 3c 28 00 0f 85 36 0a 00 00 48 8b 44 24 10 48 8b 2c c5 c0 09 c8 9b 48 8d bd 39 5f 00 00 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 2c 0a 00 00 0f b6 9d 39 5f
RSP: 0018:ffffc900036ef948 EFLAGS: 00010202
RAX: 0000000000000be7 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff886a5335 RDI: 0000000000005f39
RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000002
R10: 0000000000000003 R11: dffffc0000000000 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000004 R15: 0000000000000004
FS:  00007f751a8316c0(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561c82d2e620 CR3: 0000000059c7e000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	3c 28                	cmp    $0x28,%al
   2:	00 0f                	add    %cl,(%rdi)
   4:	85 36                	test   %esi,(%rsi)
   6:	0a 00                	or     (%rax),%al
   8:	00 48 8b             	add    %cl,-0x75(%rax)
   b:	44 24 10             	rex.R and $0x10,%al
   e:	48 8b 2c c5 c0 09 c8 	mov    -0x6437f640(,%rax,8),%rbp
  15:	9b
  16:	48 8d bd 39 5f 00 00 	lea    0x5f39(%rbp),%rdi
  1d:	48 89 f8             	mov    %rdi,%rax
  20:	48 89 fa             	mov    %rdi,%rdx
  23:	48 c1 e8 03          	shr    $0x3,%rax
  27:	83 e2 07             	and    $0x7,%edx
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	38 d0                	cmp    %dl,%al
  31:	7f 08                	jg     0x3b
  33:	84 c0                	test   %al,%al
  35:	0f 85 2c 0a 00 00    	jne    0xa67
  3b:	0f                   	.byte 0xf
  3c:	b6 9d                	mov    $0x9d,%dh
  3e:	39                   	.byte 0x39
  3f:	5f                   	pop    %rdi


---
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.

      reply	other threads:[~2026-08-26  9:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-22  2:55 [syzbot] [media?] general protection fault in vivid_probe syzbot
2026-08-26  9:43 ` syzbot [this message]

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