syzbot


general protection fault in dvb_usbv2_generic_write (2)

Status: upstream: reported C repro on 2025/12/25 21:19
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+58e3dc3a42cf1871b50e@syzkaller.appspotmail.com
First crash: 31d, last: 31d
Fix bisection: failed (error log, bisect log)
  
Bug presence (1)
Date Name Commit Repro Result
2025/12/26 upstream (ToT) ccd1cdca5cd4 C [report] general protection fault in dvb_usbv2_generic_write
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 general protection fault in dvb_usbv2_generic_write origin:upstream 2 C 29 9d13h 92d 0/3 upstream: reported C repro on 2025/10/25 16:29
upstream general protection fault in dvb_usbv2_generic_write usb media 2 C error 113 3d00h 500d 0/29 upstream: reported C repro on 2024/09/13 13:35
linux-6.1 general protection fault in dvb_usbv2_generic_write 2 1 292d 292d 0/3 auto-obsoleted due to no activity on 2025/07/18 07:04
linux-6.6 general protection fault in dvb_usbv2_generic_write origin:upstream 2 C error 3 31d 31d 0/2 upstream: reported C repro on 2025/12/25 21:19

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000019: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
CPU: 1 PID: 4731 Comm: syz.0.225 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:582 [inline]
RIP: 0010:__mutex_lock+0xdb/0xaf0 kernel/locking/mutex.c:747
Code: c0 40 f1 9c 96 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 6b 09 00 00 83 3d a2 91 83 0c 00 75 21 48 8d 7b 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 69 b1 b7 f7 48 39 5b 60 0f 85 ee 08 00 00
RSP: 0018:ffffc90003e573c0 EFLAGS: 00010202
RAX: 0000000000000019 RBX: 0000000000000068 RCX: ffffffff969cf103
RDX: ffff88802dba8000 RSI: ffffffff8a6c1780 RDI: 00000000000000c8
RBP: ffffc90003e57518 R08: ffffffff86ca34d2 R09: ffffed100b921d2c
R10: ffffed100b921d2c R11: 1ffff1100b921d2b R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805c90e958 R15: 0000000000000000
FS:  000055556597e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e563fff CR3: 000000005d731000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dvb_usbv2_generic_write+0x22/0x50 drivers/media/usb/dvb-usb-v2/dvb_usb_urb.c:77
 mxl111sf_ctrl_msg+0x15e/0x2c0 drivers/media/usb/dvb-usb-v2/mxl111sf.c:73
 mxl111sf_write_reg+0x9d/0x180 drivers/media/usb/dvb-usb-v2/mxl111sf.c:123
 mxl111sf_i2c_start drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c:130 [inline]
 mxl111sf_i2c_sw_xfer_msg drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c:-1 [inline]
 mxl111sf_i2c_xfer+0x45e/0x4ed0 drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c:813
 __i2c_transfer+0x864/0x2260 drivers/i2c/i2c-core-base.c:-1
 i2c_transfer+0x24c/0x390 drivers/i2c/i2c-core-base.c:2333
 i2cdev_ioctl_rdwr+0x3da/0x6c0 drivers/i2c/i2c-dev.c:297
 i2cdev_ioctl+0x5ba/0x750 drivers/i2c/i2c-dev.c:458
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fab9638f749
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:00007ffcb7666878 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fab965e5fa0 RCX: 00007fab9638f749
RDX: 0000200000000a40 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007fab96413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab965e5fa0 R14: 00007fab965e5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:582 [inline]
RIP: 0010:__mutex_lock+0xdb/0xaf0 kernel/locking/mutex.c:747
Code: c0 40 f1 9c 96 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 6b 09 00 00 83 3d a2 91 83 0c 00 75 21 48 8d 7b 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 69 b1 b7 f7 48 39 5b 60 0f 85 ee 08 00 00
RSP: 0018:ffffc90003e573c0 EFLAGS: 00010202
RAX: 0000000000000019 RBX: 0000000000000068 RCX: ffffffff969cf103
RDX: ffff88802dba8000 RSI: ffffffff8a6c1780 RDI: 00000000000000c8
RBP: ffffc90003e57518 R08: ffffffff86ca34d2 R09: ffffed100b921d2c
R10: ffffed100b921d2c R11: 1ffff1100b921d2b R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805c90e958 R15: 0000000000000000
FS:  000055556597e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e963fff CR3: 000000005d731000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c0 40 f1 9c          	rolb   $0x9c,-0xf(%rax)
   4:	96                   	xchg   %eax,%esi
   5:	48 c1 e8 03          	shr    $0x3,%rax
   9:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
   e:	84 c0                	test   %al,%al
  10:	0f 85 6b 09 00 00    	jne    0x981
  16:	83 3d a2 91 83 0c 00 	cmpl   $0x0,0xc8391a2(%rip)        # 0xc8391bf
  1d:	75 21                	jne    0x40
  1f:	48 8d 7b 60          	lea    0x60(%rbx),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 69 b1 b7 f7       	call   0xf7b7b19f
  36:	48 39 5b 60          	cmp    %rbx,0x60(%rbx)
  3a:	0f 85 ee 08 00 00    	jne    0x92e

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/25 22:04 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in dvb_usbv2_generic_write
2025/12/25 21:20 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in dvb_usbv2_generic_write
2025/12/25 21:19 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in dvb_usbv2_generic_write
* Struck through repros no longer work on HEAD.