Hello, When fuzzing the Linux kernel driver v6.0-rc6, the following crash was triggered. HEAD commit: 521a547ced6477c54b4b0cc206000406c221b4d6 git tree: upstream kernel config: https://pastebin.com/raw/hekxU61F console output: https://pastebin.com/raw/rNPrPV51 Sorry for failing to extract the reproducer. But on other versions of Linux, I also triggered this crash. I would appreciate it if you have any idea how to solve this bug. The crash report is as follows: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 16814 Comm: syz-executor.1 Not tainted 6.0.0-rc4+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:su3000_i2c_transfer+0x796/0xb00 drivers/media/usb/dvb-usb/dw2102.c:712 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5b 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 08 48 89 da 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 38 02 00 00 RSP: 0018:ffffc90018c8fcd8 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 0000000000040000 RDX: 0000000000000002 RSI: ffff888017691d40 RDI: ffff888064450f08 RBP: ffff88802429bd00 R08: ffffffff861e5272 R09: 0000000000001a00 R10: 0000000000000003 R11: fffffbfff1d34742 R12: ffff888024534000 R13: ffff888024534fc0 R14: ffff888024534ea0 R15: 0000000000001900 FS: 00007f4a477eb700(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a4719d060 CR3: 0000000064626000 CR4: 0000000000350ee0 Call Trace: <TASK> __i2c_transfer drivers/i2c/i2c-core-base.c:2109 [inline] __i2c_transfer+0x4c2/0x16a0 drivers/i2c/i2c-core-base.c:2074 i2c_transfer+0x1e6/0x3e0 drivers/i2c/i2c-core-base.c:2170 i2cdev_ioctl_rdwr.isra.0+0x2ea/0x6a0 drivers/i2c/i2c-dev.c:297 i2cdev_ioctl+0x488/0x7b0 drivers/i2c/i2c-dev.c:458 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4a470a80fd Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4a477eabf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4a4719c340 RCX: 00007f4a470a80fd RDX: 0000000020002180 RSI: 0000000000000707 RDI: 0000000000000003 RBP: 00007f4a4710b606 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff0c6db6ff R14: 00007fff0c6db8a0 R15: 00007f4a477ead80 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:su3000_i2c_transfer+0x796/0xb00 drivers/media/usb/dvb-usb/dw2102.c:712 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5b 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 08 48 89 da 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 38 02 00 00 RSP: 0018:ffffc90018c8fcd8 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 0000000000040000 RDX: 0000000000000002 RSI: ffff888017691d40 RDI: ffff888064450f08 RBP: ffff88802429bd00 R08: ffffffff861e5272 R09: 0000000000001a00 R10: 0000000000000003 R11: fffffbfff1d34742 R12: ffff888024534000 R13: ffff888024534fc0 R14: ffff888024534ea0 R15: 0000000000001900 FS: 00007f4a477eb700(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f18040450a8 CR3: 0000000064626000 CR4: 0000000000350ee0 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df 48 89 fisttps -0x77(%rax) 3: fa cli 4: 48 c1 ea 03 shr $0x3,%rdx 8: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) c: 0f 85 5b 03 00 00 jne 0x36d 12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 19: fc ff df 1c: 48 8b 5b 08 mov 0x8(%rbx),%rbx 20: 48 89 da mov %rbx,%rdx 23: 48 c1 ea 03 shr $0x3,%rdx * 27: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2b: 48 89 da mov %rbx,%rdx 2e: 83 e2 07 and $0x7,%edx 31: 38 d0 cmp %dl,%al 33: 7f 08 jg 0x3d 35: 84 c0 test %al,%al 37: 0f 85 38 02 00 00 jne 0x275
