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: 14683 Comm: syz.2.1645 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: 0018:ffffc90000007b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888025c5da00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff88805422c7f0
RBP: 0000000000000001 R08: ffff88805422c783 R09: 1ffff1100a8458f0
R10: dffffc0000000000 R11: ffffed100a8458f1 R12: 1ffff1100a8458fd
R13: ffffffff81a83684 R14: ffff88805422c7e8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23afbec000 CR3: 000000000df38000 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+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:memset_orig+0x15/0xb0 arch/x86/lib/memset_64.S:57
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af c1 <41> 89 f9 41 83 e1 07 75 74 48 89 d1 48 c1 e9 06 74 39 66 0f 1f 84
RSP: 0018:ffffc90003486e18 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff88805054a000 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003486e78
RBP: ffff88805054a000 R08: ffffc90003486e9f R09: 1ffff92000690dd3
R10: ffffc90003486e78 R11: fffff52000690dd4 R12: ffffc90003487100
R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
__debug_check_no_obj_freed lib/debugobjects.c:1073 [inline]
debug_check_no_obj_freed+0x4f/0x470 lib/debugobjects.c:1129
free_pages_prepare mm/page_alloc.c:1399 [inline]
free_unref_folios+0x52d/0x1570 mm/page_alloc.c:2949
folios_put_refs+0x559/0x640 mm/swap.c:992
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
zap_pte_range mm/memory.c:1792 [inline]
zap_pmd_range mm/memory.c:1845 [inline]
zap_pud_range mm/memory.c:1874 [inline]
zap_p4d_range mm/memory.c:1895 [inline]
unmap_page_range+0x38fd/0x41c0 mm/memory.c:1916
unmap_single_vma mm/memory.c:1959 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2003
exit_mmap+0x248/0xb50 mm/mmap.c:1284
__mmput+0x118/0x420 kernel/fork.c:1120
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0117900ca
Code: Unable to access opcode bytes at 0x7fb0117900a0.
RSP: 002b:00007fb01255ee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffc RBX: 00007fb01255eef0 RCX: 00007fb0117900ca
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007fb01255eeb0
RBP: 0000200000000180 R08: 00007fb01255eef0 R09: 0000000000800714
R10: 0000000000800714 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007fb01255eeb0 R14: 0000000000000485 R15: 0000200000000500
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: 0018:ffffc90000007b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888025c5da00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff88805422c7f0
RBP: 0000000000000001 R08: ffff88805422c783 R09: 1ffff1100a8458f0
R10: dffffc0000000000 R11: ffffed100a8458f1 R12: 1ffff1100a8458fd
R13: ffffffff81a83684 R14: ffff88805422c7e8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23afbec000 CR3: 000000000df38000 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