Hello, syzbot found the following issue on: HEAD commit: 568035b01cfb Linux 6.0-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1131e5e3080000 kernel config: https://syzkaller.appspot.com/x/.config?x=3b9175e0879a7749 dashboard link: https://syzkaller.appspot.com/bug?extid=c50cf81fb2c17ffb6e6b compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c50cf81fb2c17ffb6e6b@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: unable to handle page fault for address: ffffdc0000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 11826067 P4D 11826067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1105 Comm: kworker/u4:4 Not tainted 6.0.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 RIP: 0010:strnlen+0x3b/0x70 lib/string.c:504 Code: 74 3c 48 bb 00 00 00 00 00 fc ff df 49 89 fc 48 89 f8 eb 09 48 83 c0 01 48 39 e8 74 1e 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 <0f> b6 14 1a 38 ca 7f 04 84 d2 75 11 80 38 00 75 d9 4c 29 e0 48 83 RSP: 0018:ffffc90004cc7e10 EFLAGS: 00010246 RAX: ffff000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 1fffe00000000000 RSI: 0000000000020000 RDI: ffff000000000000 RBP: ffff000000020000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000000 R12: ffff000000000000 R13: ffff88801f859c00 R14: ffff000000000000 R15: ffff88801f859c00 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffdc0000000000 CR3: 000000000bc8e000 CR4: 0000000000350ef0 Call Trace: <TASK> strnlen include/linux/fortify-string.h:119 [inline] copy_string_kernel+0x26/0x250 fs/exec.c:616 copy_strings_kernel+0xb3/0x190 fs/exec.c:655 kernel_execve+0x377/0x500 fs/exec.c:2001 call_usermodehelper_exec_async+0x2e3/0x580 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Modules linked in: CR2: ffffdc0000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:strnlen+0x3b/0x70 lib/string.c:504 Code: 74 3c 48 bb 00 00 00 00 00 fc ff df 49 89 fc 48 89 f8 eb 09 48 83 c0 01 48 39 e8 74 1e 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 <0f> b6 14 1a 38 ca 7f 04 84 d2 75 11 80 38 00 75 d9 4c 29 e0 48 83 RSP: 0018:ffffc90004cc7e10 EFLAGS: 00010246 RAX: ffff000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 1fffe00000000000 RSI: 0000000000020000 RDI: ffff000000000000 RBP: ffff000000020000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000000 R12: ffff000000000000 R13: ffff88801f859c00 R14: ffff000000000000 R15: ffff88801f859c00 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffdc0000000000 CR3: 000000000bc8e000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 74 3c je 0x3e 2: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 9: fc ff df c: 49 89 fc mov %rdi,%r12 f: 48 89 f8 mov %rdi,%rax 12: eb 09 jmp 0x1d 14: 48 83 c0 01 add $0x1,%rax 18: 48 39 e8 cmp %rbp,%rax 1b: 74 1e je 0x3b 1d: 48 89 c2 mov %rax,%rdx 20: 48 89 c1 mov %rax,%rcx 23: 48 c1 ea 03 shr $0x3,%rdx 27: 83 e1 07 and $0x7,%ecx * 2a: 0f b6 14 1a movzbl (%rdx,%rbx,1),%edx <-- trapping instruction 2e: 38 ca cmp %cl,%dl 30: 7f 04 jg 0x36 32: 84 d2 test %dl,%dl 34: 75 11 jne 0x47 36: 80 38 00 cmpb $0x0,(%rax) 39: 75 d9 jne 0x14 3b: 4c 29 e0 sub %r12,%rax 3e: 48 rex.W 3f: 83 .byte 0x83 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
