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: 15 Comm: ksoftirqd/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:ffffc900001478b0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88801ceb3c00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8880333ec070 RBP: 0000000000000001 R08: ffff8880333ec003 R09: 1ffff1100667d800 R10: dffffc0000000000 R11: ffffed100667d801 R12: 1ffff1100667d80d R13: ffffffff81a8bfb4 R14: ffff8880333ec068 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe9c377e2d8 CR3: 000000007c950000 CR4: 00000000003526f0 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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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:ffffc900001478b0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88801ceb3c00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8880333ec070 RBP: 0000000000000001 R08: ffff8880333ec003 R09: 1ffff1100667d800 R10: dffffc0000000000 R11: ffffed100667d801 R12: 1ffff1100667d80d R13: ffffffff81a8bfb4 R14: ffff8880333ec068 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe9c377e2d8 CR3: 000000007c950000 CR4: 00000000003526f0 ---------------- 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