Oops: general protection fault, probably for non-canonical address 0xdffffc000000002e: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000170-0x0000000000000177] CPU: 1 UID: 0 PID: 5469 Comm: syz-executor.5 Not tainted 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:nsproxy_free+0x28a/0x5a0 Code: 02 00 00 4c 8b 65 28 4d 85 e4 74 43 e8 7f 56 30 00 49 8d bc 24 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 02 00 00 49 8b 9c 24 78 01 00 00 bf 08 00 00 RSP: 0018:ffff8880167dfdc8 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc90003ea9000 RDX: 000000000000002e RSI: ffffffff8144dd61 RDI: 0000000000000174 RBP: ffff88800974f548 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8664ed57 R11: 0000000000000001 R12: fffffffffffffffc R13: ffff88800da6341c R14: ffffffff85cfdf20 R15: ffff88800e998878 FS: 00007f98a262e700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2dd2a000 CR3: 000000000f8ea000 CR4: 0000000000350ef0 Call Trace: create_new_namespaces+0x585/0x750 unshare_nsproxy_namespaces+0xc0/0x200 ksys_unshare+0x468/0xa10 __x64_sys_unshare+0x31/0x40 do_syscall_64+0xbf/0x430 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f98a50d9b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f98a262e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f98a51ed020 RCX: 00007f98a50d9b19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000046020400 RBP: 00007f98a5133f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd4af7fb0f R14: 00007f98a262e300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:nsproxy_free+0x28a/0x5a0 Code: 02 00 00 4c 8b 65 28 4d 85 e4 74 43 e8 7f 56 30 00 49 8d bc 24 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 02 00 00 49 8b 9c 24 78 01 00 00 bf 08 00 00 RSP: 0018:ffff8880167dfdc8 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc90003ea9000 RDX: 000000000000002e RSI: ffffffff8144dd61 RDI: 0000000000000174 RBP: ffff88800974f548 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8664ed57 R11: 0000000000000001 R12: fffffffffffffffc R13: ffff88800da6341c R14: ffffffff85cfdf20 R15: ffff88800e998878 FS: 00007f98a262e700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2dd2a000 CR3: 000000000f8ea000 CR4: 0000000000350ef0 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 UID: 0 PID: 5485 Comm: syz-executor.0 Tainted: G D 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) Tainted: [D]=DIE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xfa/0x120 should_fail_ex+0x4d7/0x5e0 should_failslab+0xc2/0x120 kmem_cache_alloc_noprof+0x80/0x690 __kernfs_new_node+0xd3/0x870 kernfs_new_node+0x13c/0x1e0 __kernfs_create_file+0x55/0x360 sysfs_add_file_mode_ns+0x21c/0x440 internal_create_group+0x571/0xeb0 loop_configure+0xc46/0x15a0 lo_ioctl+0x66d/0x1ca0 blkdev_ioctl+0x365/0x6d0 __x64_sys_ioctl+0x18f/0x210 do_syscall_64+0xbf/0x430 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f52360788d7 Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 54 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f52335edf48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f52360c2970 RCX: 00007f52360788d7 RDX: 0000000000000005 RSI: 0000000000004c00 RDI: 0000000000000006 RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000005 R14: 0000000020000200 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 02 00 add (%rax),%al 2: 00 4c 8b 65 add %cl,0x65(%rbx,%rcx,4) 6: 28 4d 85 sub %cl,-0x7b(%rbp) 9: e4 74 in $0x74,%al b: 43 e8 7f 56 30 00 rex.XB callq 0x305690 11: 49 8d bc 24 78 01 00 lea 0x178(%r12),%rdi 18: 00 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 f7 02 00 00 jne 0x32b 34: 49 8b 9c 24 78 01 00 mov 0x178(%r12),%rbx 3b: 00 3c: bf .byte 0xbf 3d: 08 00 or %al,(%rax)