syzbot


general protection fault in dvb_usbv2_generic_write

Status: upstream: reported on 2025/04/09 07:04
Reported-by: syzbot+a358cdabe781f8c4253a@syzkaller.appspotmail.com
First crash: 79d, last: 79d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in dvb_usbv2_generic_write media C error 35 12h30m 287d 0/29 upstream: reported C repro on 2024/09/13 13:35

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: 0 PID: 10189 Comm: syz.0.1645 Not tainted 6.1.133-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:582 [inline]
RIP: 0010:__mutex_lock+0xee/0xd80 kernel/locking/mutex.c:747
Code: c0 60 31 3c 97 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 97 0b 00 00 83 3d af 7a 81 0c 00 75 21 49 8d 7d 60 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 c6 54 27 f7 4d 39 6d 60 0f 85 13 0b 00 00
RSP: 0018:ffffc90003307180 EFLAGS: 00010202
RAX: 0000000000000019 RBX: 0000000000000000 RCX: ffffffff973c3103
RDX: dffffc0000000000 RSI: ffff88802fa88000 RDI: 00000000000000c8
RBP: ffffc900033072d0 R08: dffffc0000000000 R09: ffffc90003307220
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000068 R14: 0000000000000000 R15: ffff88807b010958
FS:  00007f6c9ec9e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002580 CR3: 0000000078cba000 CR4: 00000000003506f0
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+0x16a/0x2d0 drivers/media/usb/dvb-usb-v2/mxl111sf.c:73
 mxl111sf_write_reg+0xd4/0x1e0 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+0x91a/0x8a20 drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c:813
 __i2c_transfer+0x850/0x2380 drivers/i2c/i2c-core-base.c:-1
 i2c_transfer+0x261/0x3a0 drivers/i2c/i2c-core-base.c:2333
 i2cdev_ioctl_rdwr+0x3da/0x6b0 drivers/i2c/i2c-dev.c:297
 i2cdev_ioctl+0x6d6/0x950 drivers/i2c/i2c-dev.c:458
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6c9dd8d169
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:00007f6c9ec9e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6c9dfa5fa0 RCX: 00007f6c9dd8d169
RDX: 0000200000002580 RSI: 0000000000000707 RDI: 0000000000000004
RBP: 00007f6c9de0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6c9dfa5fa0 R15: 00007ffd7249c8f8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:582 [inline]
RIP: 0010:__mutex_lock+0xee/0xd80 kernel/locking/mutex.c:747
Code: c0 60 31 3c 97 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 97 0b 00 00 83 3d af 7a 81 0c 00 75 21 49 8d 7d 60 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 c6 54 27 f7 4d 39 6d 60 0f 85 13 0b 00 00
RSP: 0018:ffffc90003307180 EFLAGS: 00010202
RAX: 0000000000000019 RBX: 0000000000000000 RCX: ffffffff973c3103
RDX: dffffc0000000000 RSI: ffff88802fa88000 RDI: 00000000000000c8
RBP: ffffc900033072d0 R08: dffffc0000000000 R09: ffffc90003307220
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000068 R14: 0000000000000000 R15: ffff88807b010958
FS:  00007f6c9ec9e6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da1aff8 CR3: 0000000078cba000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c0 60 31 3c          	shlb   $0x3c,0x31(%rax)
   4:	97                   	xchg   %eax,%edi
   5:	48 c1 e8 03          	shr    $0x3,%rax
   9:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
   e:	84 c0                	test   %al,%al
  10:	0f 85 97 0b 00 00    	jne    0xbad
  16:	83 3d af 7a 81 0c 00 	cmpl   $0x0,0xc817aaf(%rip)        # 0xc817acc
  1d:	75 21                	jne    0x40
  1f:	49 8d 7d 60          	lea    0x60(%r13),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 c6 54 27 f7       	call   0xf72754fc
  36:	4d 39 6d 60          	cmp    %r13,0x60(%r13)
  3a:	0f 85 13 0b 00 00    	jne    0xb53

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/09 07:03 linux-6.1.y 3dfebb87d7eb a775275d .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.