[syzbot] [media?] general protection fault in mxl111sf_get_stream_config_atsc_mh

[syzbot] [media?] general protection fault in mxl111sf_get_stream_config_atsc_mh

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    c03c1a14507d Linux 7.3
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1168a305580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f
dashboard link: https://syzkaller.appspot.com/bug?extid=ffac2da5e6f8ad2671b2
compiler:       Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=127cc081580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ffac2da5e6f8ad2671b2@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000a1: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000508-0x000000000000050f]
CPU: 1 UID: 0 PID: 5937 Comm: syz-executor260 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:mxl111sf_get_stream_config_atsc_mh+0x3e/0x9d0 drivers/media/usb/dvb-usb-v2/mxl111sf.c:1193
Code: 49 89 ff 49 bd 00 00 00 00 00 fc ff df e8 0a 54 92 f9 0f 1f 44 00 00 e8 00 54 92 f9 49 81 c7 08 05 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 e7 03 00 00 45 8b 3f 4c 89 ff 48 c7 c6
RSP: 0018:ffffc9000345fb28 EFLAGS: 00010202
RAX: 00000000000000a1 RBX: ffffc9000345fbc0 RCX: ffff888077398000
RDX: 0000000000000000 RSI: ffff888058feca19 RDI: 0000000000000000
RBP: ffffc9000345fc38 R08: 0000001800060502 R09: 0000000100000c00
R10: 0000001800060502 R11: ffffffff8835bdd0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888058feca19 R15: 0000000000000508
FS:  00007f554a6f06c0(0000) GS:ffff888123bbf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc031d500f5 CR3: 0000000034892000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 dvb_usb_start_feed+0x361/0xc70 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:271
 dmx_ts_feed_start_filtering+0x129/0x220 drivers/media/dvb-core/dvb_demux.c:747
 dvb_dmxdev_start_feed drivers/media/dvb-core/dmxdev.c:658 [inline]
 dvb_dmxdev_filter_start+0x434/0x10d0 drivers/media/dvb-core/dmxdev.c:769
 dvb_demux_do_ioctl+0x48b/0x540 drivers/media/dvb-core/dmxdev.c:1099
 dvb_usercopy+0x199/0x2e0 drivers/media/dvb-core/dvbdev.c:996
 dvb_demux_ioctl+0x29/0x40 drivers/media/dvb-core/dmxdev.c:1208
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f554a728c1b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f554a6efe30 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f554a728c1b
RDX: 00007f554a6efe90 RSI: 0000000040146f2c RDI: 0000000000000008
RBP: 00007f554a796625 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f554a79644d
R13: 00007f554a7c1598 R14: 00007f5540000b70 R15: 00007f554a7c15b0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:mxl111sf_get_stream_config_atsc_mh+0x3e/0x9d0 drivers/media/usb/dvb-usb-v2/mxl111sf.c:1193
Code: 49 89 ff 49 bd 00 00 00 00 00 fc ff df e8 0a 54 92 f9 0f 1f 44 00 00 e8 00 54 92 f9 49 81 c7 08 05 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 e7 03 00 00 45 8b 3f 4c 89 ff 48 c7 c6
RSP: 0018:ffffc9000345fb28 EFLAGS: 00010202
RAX: 00000000000000a1 RBX: ffffc9000345fbc0 RCX: ffff888077398000
RDX: 0000000000000000 RSI: ffff888058feca19 RDI: 0000000000000000
RBP: ffffc9000345fc38 R08: 0000001800060502 R09: 0000000100000c00
R10: 0000001800060502 R11: ffffffff8835bdd0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888058feca19 R15: 0000000000000508
FS:  00007f554a6f06c0(0000) GS:ffff888123bbf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc031d500f5 CR3: 0000000034892000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	49 89 ff             	mov    %rdi,%r15
   3:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
   a:	fc ff df
   d:	e8 0a 54 92 f9       	call   0xf992541c
  12:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  17:	e8 00 54 92 f9       	call   0xf992541c
  1c:	49 81 c7 08 05 00 00 	add    $0x508,%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 e7 03 00 00    	jne    0x41e
  37:	45 8b 3f             	mov    (%r15),%r15d
  3a:	4c 89 ff             	mov    %r15,%rdi
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c6                   	.byte 0xc6


---
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