================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline] BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline] BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline] BUG: KASAN: use-after-free in __run_timers+0x759/0xb60 kernel/time/timer.c:1817 Write of size 8 at addr ffff8881d34431c8 by task syz.4.1967/5566 CPU: 0 PID: 5566 Comm: syz.4.1967 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack+0x1e/0x20 lib/dump_stack.c:77 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384 __kasan_report+0xef/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137 __hlist_del include/linux/list.h:791 [inline] detach_timer kernel/time/timer.c:824 [inline] expire_timers kernel/time/timer.c:1482 [inline] __run_timers+0x759/0xb60 kernel/time/timer.c:1817 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830 __do_softirq+0x236/0x660 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x197/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:unwind_done arch/x86/include/asm/unwind.h:46 [inline] RIP: 0010:__unwind_start+0x32d/0x3a0 arch/x86/kernel/unwind_frame.c:407 Code: b8 74 08 48 89 df e8 72 cb 5f 00 48 8b 45 c8 48 39 03 73 41 4c 89 f7 e8 f1 ed ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 4d d0 <0f> b6 04 01 84 c0 75 0c 41 83 3e 00 0f 85 1f ff ff ff eb 17 44 89 RSP: 0018:ffff8881e52cf7d0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff8881e52cf880 RCX: 1ffff1103ca59f09 RDX: ffff8881e52cf8d0 RSI: 1ffff1103ca59f0a RDI: ffff8881e52cf8a0 RBP: ffff8881e52cf838 R08: dffffc0000000000 R09: ffff8881e52cf848 R10: ffffed103ca59f15 R11: 1ffff1103ca59f09 R12: ffff8881e52cf858 R13: ffff8881e52cf850 R14: ffff8881e52cf848 R15: 1ffff1103ca59f0b unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xd8/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543 kmem_cache_alloc_trace+0x112/0x290 mm/slub.c:2856 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] selinux_sk_alloc_security+0x78/0x190 security/selinux/hooks.c:5247 security_sk_alloc+0x72/0xa0 security/security.c:2108 sk_prot_alloc+0x133/0x410 net/core/sock.c:1625 sk_alloc+0x38/0x330 net/core/sock.c:1680 unix_create1+0x90/0x5a0 net/unix/af_unix.c:789 unix_create+0x135/0x1c0 net/unix/af_unix.c:850 __sock_create+0x3a8/0x740 net/socket.c:1427 sock_create net/socket.c:1478 [inline] __sys_socketpair+0x1a7/0x5a0 net/socket.c:1578 __do_sys_socketpair net/socket.c:1631 [inline] __se_sys_socketpair net/socket.c:1628 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1628 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f0fea6d8969 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0fe8d41038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f0fea8fffa0 RCX: 00007f0fea6d8969 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00007f0fea75aab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0fea8fffa0 R15: 00007ffd4ec2bed8 The buggy address belongs to the page: page:ffffea00074d10c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007205b48 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x152dc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x35e/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894 __alloc_pages include/linux/gfp.h:503 [inline] __alloc_pages_node include/linux/gfp.h:516 [inline] alloc_pages_node include/linux/gfp.h:530 [inline] kmalloc_order mm/slab_common.c:1342 [inline] kmalloc_order_trace+0x31/0x100 mm/slab_common.c:1358 kmalloc_large include/linux/slab.h:485 [inline] __kmalloc+0x162/0x2f0 mm/slub.c:3902 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x88/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvzalloc include/linux/mm.h:769 [inline] bpf_check+0xfb/0x9cf0 kernel/bpf/verifier.c:9561 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] __free_pages_ok+0x7e4/0x910 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4956 [inline] __free_pages+0x8c/0x110 mm/page_alloc.c:4962 kfree+0x1ca/0x260 mm/slub.c:4068 kvfree+0x4c/0x50 mm/util.c:625 bpf_check+0x8371/0x9cf0 kernel/bpf/verifier.c:9731 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881d3443080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d3443100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881d3443180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881d3443200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d3443280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1d5f16067 P4D 1d5f16067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5566 Comm: syz.4.1967 Tainted: G B 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ec850000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d34431c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffbcd8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d34431c0 FS: 00007f0fe8d416c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001f3fe0000 CR4: 00000000003406b0 DR0: 0040000100000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x81d/0xb60 kernel/time/timer.c:1817 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830 __do_softirq+0x236/0x660 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x197/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:unwind_done arch/x86/include/asm/unwind.h:46 [inline] RIP: 0010:__unwind_start+0x32d/0x3a0 arch/x86/kernel/unwind_frame.c:407 Code: b8 74 08 48 89 df e8 72 cb 5f 00 48 8b 45 c8 48 39 03 73 41 4c 89 f7 e8 f1 ed ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 4d d0 <0f> b6 04 01 84 c0 75 0c 41 83 3e 00 0f 85 1f ff ff ff eb 17 44 89 RSP: 0018:ffff8881e52cf7d0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff8881e52cf880 RCX: 1ffff1103ca59f09 RDX: ffff8881e52cf8d0 RSI: 1ffff1103ca59f0a RDI: ffff8881e52cf8a0 RBP: ffff8881e52cf838 R08: dffffc0000000000 R09: ffff8881e52cf848 R10: ffffed103ca59f15 R11: 1ffff1103ca59f09 R12: ffff8881e52cf858 R13: ffff8881e52cf850 R14: ffff8881e52cf848 R15: 1ffff1103ca59f0b unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xd8/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543 kmem_cache_alloc_trace+0x112/0x290 mm/slub.c:2856 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] selinux_sk_alloc_security+0x78/0x190 security/selinux/hooks.c:5247 security_sk_alloc+0x72/0xa0 security/security.c:2108 sk_prot_alloc+0x133/0x410 net/core/sock.c:1625 sk_alloc+0x38/0x330 net/core/sock.c:1680 unix_create1+0x90/0x5a0 net/unix/af_unix.c:789 unix_create+0x135/0x1c0 net/unix/af_unix.c:850 __sock_create+0x3a8/0x740 net/socket.c:1427 sock_create net/socket.c:1478 [inline] __sys_socketpair+0x1a7/0x5a0 net/socket.c:1578 __do_sys_socketpair net/socket.c:1631 [inline] __se_sys_socketpair net/socket.c:1628 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1628 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f0fea6d8969 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0fe8d41038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f0fea8fffa0 RCX: 00007f0fea6d8969 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00007f0fea75aab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0fea8fffa0 R15: 00007ffd4ec2bed8 Modules linked in: CR2: 0000000000000000 ---[ end trace 2bca21a1b8de1070 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ec850000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d34431c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffbcd8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d34431c0 FS: 00007f0fe8d416c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001f3fe0000 CR4: 00000000003406b0 DR0: 0040000100000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: b8 74 08 48 89 mov $0x89480874,%eax 5: df e8 fucomip %st(0),%st 7: 72 cb jb 0xffffffd4 9: 5f pop %rdi a: 00 48 8b add %cl,-0x75(%rax) d: 45 c8 48 39 03 rex.RB enter $0x3948,$0x3 12: 73 41 jae 0x55 14: 4c 89 f7 mov %r14,%rdi 17: e8 f1 ed ff ff call 0xffffee0d 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df 26: 48 8b 4d d0 mov -0x30(%rbp),%rcx * 2a: 0f b6 04 01 movzbl (%rcx,%rax,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 75 0c jne 0x3e 32: 41 83 3e 00 cmpl $0x0,(%r14) 36: 0f 85 1f ff ff ff jne 0xffffff5b 3c: eb 17 jmp 0x55 3e: 44 rex.R 3f: 89 .byte 0x89