RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004c80 RDX: 0000000099999999 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 10b768067 P4D 10b768067 PUD 103fea067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 3033 Comm: syz-executor.0 Not tainted 6.5.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:strchr+0x4/0x30 lib/string.c:329 Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 40 00 f3 0f 1e fa <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c7 01 38 d0 RSP: 0018:ffffc90001abfcf8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888104321b40 RSI: 0000000000000025 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc90001abfd48 R13: 0000000000000cc0 R14: 0000000000000000 R15: ffff8881104d43f0 FS: 0000000000000000(0000) GS:ffff888237c00000(0063) knlGS:00000000f6ed8b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001056fb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvasprintf_const+0x25/0x110 lib/kasprintf.c:45 kobject_set_name_vargs+0x40/0xd0 lib/kobject.c:272 kobject_add_varg lib/kobject.c:366 [inline] kobject_add+0xaf/0x140 lib/kobject.c:424 device_add+0x153/0xd40 drivers/base/core.c:3562 device_add_disk+0x167/0x5e0 block/genhd.c:456 add_disk include/linux/blkdev.h:734 [inline] loop_add+0x3c0/0x460 drivers/block/loop.c:2087 loop_control_ioctl+0xcf/0x380 drivers/block/loop.c:2210 __do_compat_sys_ioctl+0x27c/0x2d0 fs/ioctl.c:968 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xd0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf72dd579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f6ed85ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004c80 RDX: 0000000099999999 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:strchr+0x4/0x30 lib/string.c:329 Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 40 00 f3 0f 1e fa <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c7 01 38 d0 RSP: 0018:ffffc90001abfcf8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888104321b40 RSI: 0000000000000025 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc90001abfd48 R13: 0000000000000cc0 R14: 0000000000000000 R15: ffff8881104d43f0 FS: 0000000000000000(0000) GS:ffff888237c00000(0063) knlGS:00000000f6ed8b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001056fb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: c0 eb 0d shr $0xd,%bl 3: 84 c9 test %cl,%cl 5: 74 18 je 0x1f 7: 48 83 c0 01 add $0x1,%rax b: 48 39 d0 cmp %rdx,%rax e: 74 0f je 0x1f 10: 0f b6 0c 07 movzbl (%rdi,%rax,1),%ecx 14: 3a 0c 06 cmp (%rsi,%rax,1),%cl 17: 74 ea je 0x3 19: 19 c0 sbb %eax,%eax 1b: 83 c8 01 or $0x1,%eax 1e: c3 ret 1f: 31 c0 xor %eax,%eax 21: c3 ret 22: 0f 1f 40 00 nopl 0x0(%rax) 26: f3 0f 1e fa endbr64 * 2a: 0f b6 07 movzbl (%rdi),%eax <-- trapping instruction 2d: 89 f2 mov %esi,%edx 2f: 40 38 f0 cmp %sil,%al 32: 75 0e jne 0x42 34: eb 13 jmp 0x49 36: 0f b6 47 01 movzbl 0x1(%rdi),%eax 3a: 48 83 c7 01 add $0x1,%rdi 3e: 38 d0 cmp %dl,%al