================================================================== 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 ffff8881da2771c8 by task syz.5.245/1352 CPU: 0 PID: 1352 Comm: syz.5.245 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:find_stack lib/stackdepot.c:185 [inline] RIP: 0010:stack_depot_save+0x164/0x4c0 lib/stackdepot.c:245 Code: 44 89 e3 81 e3 ff ff 0f 00 4c 8b 2c dd 80 18 5c 86 4d 85 ed 74 59 44 89 ff eb 09 4d 8b 6d 00 4d 85 ed 74 4b 45 39 65 08 75 f1 <45> 39 7d 0c 75 eb 31 c9 49 8b 34 ce 49 3b 74 cd 18 75 de 48 ff c1 RSP: 0018:ffff8881e780f480 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 000000000002bbe0 RCX: 00000000c3c67aa7 RDX: 0000000000082a20 RSI: 00000000ebacded8 RDI: 000000000000000e RBP: ffff8881e780f4d0 R08: 00000000a51311c9 R09: 00000000e9235062 R10: 0000000098228d56 R11: 000000009229969f R12: 000000001502bbe0 R13: ffff8881d7e07950 R14: ffff8881e780f500 R15: 000000000000000e save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x1c3/0x200 mm/kasan/common.c:529 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc_track_caller+0x10d/0x2d0 mm/slub.c:4449 __kmalloc_reserve net/core/skbuff.c:142 [inline] pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653 skb_ensure_writable+0x2e7/0x460 net/core/skbuff.c:5569 __bpf_try_make_writable net/core/filter.c:1635 [inline] bpf_try_make_writable net/core/filter.c:1641 [inline] bpf_try_make_head_writable net/core/filter.c:1649 [inline] ____bpf_clone_redirect net/core/filter.c:2145 [inline] bpf_clone_redirect+0x10b/0x380 net/core/filter.c:2123 bpf_prog_6893982b85ceadf7+0x4b1/0x1000 bpf_call_func include/linux/filter.h:627 [inline] bpf_test_run+0x1ea/0x5d0 net/bpf/test_run.c:44 bpf_prog_test_run_skb+0x721/0xdc0 net/bpf/test_run.c:311 bpf_prog_test_run+0x21a/0x2a0 kernel/bpf/syscall.c:2124 __do_sys_bpf kernel/bpf/syscall.c:2909 [inline] __se_sys_bpf+0x49a/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 RIP: 0033:0x7f3ec6adf969 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:00007f3ec5148038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3ec6d06fa0 RCX: 00007f3ec6adf969 RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007f3ec6b61ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3ec6d06fa0 R15: 00007ffdebf237d8 Allocated by task 1080: 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_slab_alloc+0x12/0x20 mm/kasan/common.c:537 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842 shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719 alloc_inode fs/inode.c:231 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:966 new_inode+0x28/0x1e0 fs/inode.c:995 shmem_get_inode+0x107/0x630 mm/shmem.c:2252 shmem_mknod+0x5c/0x1c0 mm/shmem.c:2844 shmem_create+0x2b/0x40 mm/shmem.c:2904 lookup_open fs/namei.c:3379 [inline] do_last fs/namei.c:3471 [inline] path_openat+0x1603/0x35c0 fs/namei.c:3683 do_filp_open+0x1ae/0x3f0 fs/namei.c:3713 do_sys_open+0x2bb/0x5d0 fs/open.c:1123 __do_sys_openat fs/open.c:1150 [inline] __se_sys_openat fs/open.c:1144 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1144 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 17: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10c/0x2c0 mm/slub.c:3096 shmem_free_in_core_inode+0x90/0xb0 mm/shmem.c:3729 i_callback+0x4c/0x70 fs/inode.c:220 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch+0x446/0x980 kernel/rcu/tree.c:2167 rcu_core+0x4bd/0xbd0 kernel/rcu/tree.c:2387 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2396 __do_softirq+0x236/0x660 kernel/softirq.c:292 The buggy address belongs to the object at ffff8881da277090 which belongs to the cache shmem_inode_cache of size 760 The buggy address is located 312 bytes inside of 760-byte region [ffff8881da277090, ffff8881da277388) The buggy address belongs to the page: page:ffffea0007689d00 refcount:1 mapcount:0 mapping:ffff8881f5d03900 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d03900 raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) 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_slab_page+0x3c/0x3b0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x93/0x420 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x29e/0x420 mm/slub.c:2667 __slab_alloc+0x63/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842 shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719 alloc_inode fs/inode.c:231 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:966 new_inode+0x28/0x1e0 fs/inode.c:995 shmem_get_inode+0x107/0x630 mm/shmem.c:2252 shmem_mknod+0x5c/0x1c0 mm/shmem.c:2844 shmem_create+0x2b/0x40 mm/shmem.c:2904 lookup_open fs/namei.c:3379 [inline] do_last fs/namei.c:3471 [inline] path_openat+0x1603/0x35c0 fs/namei.c:3683 do_filp_open+0x1ae/0x3f0 fs/namei.c:3713 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: ffff8881da277080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881da277100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881da277180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881da277200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881da277280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1e4a01067 P4D 1e4a01067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1352 Comm: syz.5.245 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: 00010002 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881ec8fbf00 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881da2771c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffada0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881da2771c0 FS: 00007f3ec51486c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001d6b68000 CR4: 00000000003406b0 DR0: 0000200000000300 DR1: 0000200000000300 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:1488 [inline] __run_timers+0x84b/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:find_stack lib/stackdepot.c:185 [inline] RIP: 0010:stack_depot_save+0x164/0x4c0 lib/stackdepot.c:245 Code: 44 89 e3 81 e3 ff ff 0f 00 4c 8b 2c dd 80 18 5c 86 4d 85 ed 74 59 44 89 ff eb 09 4d 8b 6d 00 4d 85 ed 74 4b 45 39 65 08 75 f1 <45> 39 7d 0c 75 eb 31 c9 49 8b 34 ce 49 3b 74 cd 18 75 de 48 ff c1 RSP: 0018:ffff8881e780f480 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 000000000002bbe0 RCX: 00000000c3c67aa7 RDX: 0000000000082a20 RSI: 00000000ebacded8 RDI: 000000000000000e RBP: ffff8881e780f4d0 R08: 00000000a51311c9 R09: 00000000e9235062 R10: 0000000098228d56 R11: 000000009229969f R12: 000000001502bbe0 R13: ffff8881d7e07950 R14: ffff8881e780f500 R15: 000000000000000e save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x1c3/0x200 mm/kasan/common.c:529 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc_track_caller+0x10d/0x2d0 mm/slub.c:4449 __kmalloc_reserve net/core/skbuff.c:142 [inline] pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653 skb_ensure_writable+0x2e7/0x460 net/core/skbuff.c:5569 __bpf_try_make_writable net/core/filter.c:1635 [inline] bpf_try_make_writable net/core/filter.c:1641 [inline] bpf_try_make_head_writable net/core/filter.c:1649 [inline] ____bpf_clone_redirect net/core/filter.c:2145 [inline] bpf_clone_redirect+0x10b/0x380 net/core/filter.c:2123 bpf_prog_6893982b85ceadf7+0x4b1/0x1000 bpf_call_func include/linux/filter.h:627 [inline] bpf_test_run+0x1ea/0x5d0 net/bpf/test_run.c:44 bpf_prog_test_run_skb+0x721/0xdc0 net/bpf/test_run.c:311 bpf_prog_test_run+0x21a/0x2a0 kernel/bpf/syscall.c:2124 __do_sys_bpf kernel/bpf/syscall.c:2909 [inline] __se_sys_bpf+0x49a/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 RIP: 0033:0x7f3ec6adf969 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:00007f3ec5148038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3ec6d06fa0 RCX: 00007f3ec6adf969 RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007f3ec6b61ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3ec6d06fa0 R15: 00007ffdebf237d8 Modules linked in: CR2: 0000000000000000 ---[ end trace 0852cef66a4964ed ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010002 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881ec8fbf00 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881da2771c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffada0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881da2771c0 FS: 00007f3ec51486c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001d6b68000 CR4: 00000000003406b0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 44 89 e3 mov %r12d,%ebx 3: 81 e3 ff ff 0f 00 and $0xfffff,%ebx 9: 4c 8b 2c dd 80 18 5c mov -0x79a3e780(,%rbx,8),%r13 10: 86 11: 4d 85 ed test %r13,%r13 14: 74 59 je 0x6f 16: 44 89 ff mov %r15d,%edi 19: eb 09 jmp 0x24 1b: 4d 8b 6d 00 mov 0x0(%r13),%r13 1f: 4d 85 ed test %r13,%r13 22: 74 4b je 0x6f 24: 45 39 65 08 cmp %r12d,0x8(%r13) 28: 75 f1 jne 0x1b * 2a: 45 39 7d 0c cmp %r15d,0xc(%r13) <-- trapping instruction 2e: 75 eb jne 0x1b 30: 31 c9 xor %ecx,%ecx 32: 49 8b 34 ce mov (%r14,%rcx,8),%rsi 36: 49 3b 74 cd 18 cmp 0x18(%r13,%rcx,8),%rsi 3b: 75 de jne 0x1b 3d: 48 ff c1 inc %rcx