Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 9359 Comm: syz.2.1539 Not tainted 6.16.0-rc3-next-20250623-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 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74 RSP: 0000:ffffc90003ddfad0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802569bc00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888030de8c70 RBP: 0000000000000001 R08: ffff888030de8c03 R09: 1ffff110061bd180 R10: dffffc0000000000 R11: ffffed10061bd181 R12: 1ffff110061bd18d R13: ffffffff81a83684 R14: ffff888030de8c68 R15: dffffc0000000000 FS: 00007f6168be26c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f615e179000 CR3: 0000000050202000 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+0x283/0x870 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+0x57/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f6167c50d46 Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 RSP: 002b:00007f6168be14a0 EFLAGS: 00000202 RAX: 0000000000b79cfc RBX: 00007f6168be1540 RCX: 0000000000000082 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f6168be15e0 RBP: 0000000000000102 R08: 00007f615d600000 R09: 0000000000b79cfb R10: 0000000000000000 R11: 00007f6168be1550 R12: 0000000000000001 R13: 00007f6167e2c120 R14: 0000000000000000 R15: 00007f6168be15e0 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 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74 RSP: 0000:ffffc90003ddfad0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802569bc00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888030de8c70 RBP: 0000000000000001 R08: ffff888030de8c03 R09: 1ffff110061bd180 R10: dffffc0000000000 R11: ffffed10061bd181 R12: 1ffff110061bd18d R13: ffffffff81a83684 R14: ffff888030de8c68 R15: dffffc0000000000 FS: 00007f6168be26c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f615e179000 CR3: 0000000050202000 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 a7 1b de ff call 0xffde1bbb 14: 49 83 3e 00 cmpq $0x0,(%r14) 18: 0f 85 84 00 00 00 jne 0xa2 1e: e8 08 f2 79 ff call 0xff79f22b 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 82 1b de ff call 0xffde1bbb 39: 4c 8b 33 mov (%rbx),%r14 3c: 4d 85 f6 test %r14,%r14 3f: 74 .byte 0x74