Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc2-next-20250620-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162 Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 67 19 de ff 49 83 3e 00 0f 85 84 00 00 00 e8 78 ee 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 42 19 de ff 4c 8b 33 4d 85 f6 74 RSP: 0018:ffffc90000007b90 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8de95280 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff88807ca95570 RBP: 0000000000000001 R08: ffff88807ca95503 R09: 1ffff1100f952aa0 R10: dffffc0000000000 R11: ffffed100f952aa1 R12: 1ffff1100f952aad R13: ffffffff81a8bfb4 R14: ffff88807ca95568 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558240be6008 CR3: 000000002fee2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_pid+0x9c/0x130 kernel/pid.c:103 rcu_do_batch kernel/rcu/tree.c:2582 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2838 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 43 dd 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 d5 1a 00 f3 0f 1e fa fb f4 18 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: 97c5e0cbeae3ed00 RBX: ffffffff81975fd8 RCX: 97c5e0cbeae3ed00 RDX: 0000000000000001 RSI: ffffffff8d991d22 RDI: ffffffff8be320a0 RBP: ffffffff8de07ea8 R08: ffff8880b8632f1b R09: 1ffff110170c65e3 R10: dffffc0000000000 R11: ffffed10170c65e4 R12: ffffffff8fa193f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162 Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 67 19 de ff 49 83 3e 00 0f 85 84 00 00 00 e8 78 ee 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 42 19 de ff 4c 8b 33 4d 85 f6 74 RSP: 0018:ffffc90000007b90 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8de95280 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff88807ca95570 RBP: 0000000000000001 R08: ffff88807ca95503 R09: 1ffff1100f952aa0 R10: dffffc0000000000 R11: ffffed100f952aa1 R12: 1ffff1100f952aad R13: ffffffff81a8bfb4 R14: ffff88807ca95568 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558240be6008 CR3: 000000002fee2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: f0 ff lock (bad) 2: ff 73 e4 push -0x1c(%rbx) 5: 43 80 3c 3c 00 cmpb $0x0,(%r12,%r15,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 67 19 de ff call 0xffde197b 14: 49 83 3e 00 cmpq $0x0,(%r14) 18: 0f 85 84 00 00 00 jne 0xa2 1e: e8 78 ee 79 ff call 0xff79ee9b 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 42 19 de ff call 0xffde197b 39: 4c 8b 33 mov (%rbx),%r14 3c: 4d 85 f6 test %r14,%r14 3f: 74 .byte 0x74