================================================================== 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+0x7be/0xbe0 kernel/time/timer.c:1817 Write of size 8 at addr ffff8881d4efb1c8 by task syz.9.1303/5283 CPU: 1 PID: 5283 Comm: syz.9.1303 Tainted: G W 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __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+0x7be/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:__unqueue_futex kernel/futex.c:1545 [inline] RIP: 0010:mark_wake_futex+0x10e/0x1f0 kernel/futex.c:1568 Code: d6 0a 00 09 dd 0f 88 d0 00 00 00 e8 4c d3 0a 00 4d 8d 75 30 4d 89 f4 49 c1 ec 03 43 80 3c 3c 00 74 08 4c 89 f7 e8 62 bd 3a 00 <4d> 8b 3e 4d 85 ff 0f 84 bc 00 00 00 49 8d 5d 18 48 89 d8 48 c1 e8 RSP: 0018:ffff8881f57df9f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff815977b4 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9000314a000 RSI: 000000000000606a RDI: 000000000000606b RBP: 0000000000000003 R08: ffffffff815977a7 R09: ffffed103bdb6bd5 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103c8e2f58 R13: ffff8881e4717a90 R14: ffff8881e4717ac0 R15: dffffc0000000000 futex_wake+0x4f1/0x840 kernel/futex.c:1717 do_futex+0x13fe/0x19f0 kernel/futex.c:3893 __do_sys_futex kernel/futex.c:3949 [inline] __se_sys_futex+0x355/0x470 kernel/futex.c:3917 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7fc3e1071169 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:00007fc3df6db0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fc3e1289fa8 RCX: 00007fc3e1071169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fc3e1289fac RBP: 00007fc3e1289fa0 R08: 00007ffc95bac0b0 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fc3e1289fac R13: 0000000000000000 R14: 00007ffc95afe800 R15: 00007ffc95afe8e8 The buggy address belongs to the page: page:ffffea000753bec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea00073c9e48 ffffea000753be88 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 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 __vmalloc_area_node mm/vmalloc.c:2431 [inline] __vmalloc_node_range+0x384/0x710 mm/vmalloc.c:2499 vmalloc_user+0x70/0x80 mm/vmalloc.c:2629 kcov_mmap+0x28/0x120 kernel/kcov.c:450 call_mmap include/linux/fs.h:1996 [inline] mmap_region+0x110d/0x16f0 mm/mmap.c:1812 do_mmap+0x822/0xd30 mm/mmap.c:1581 do_mmap_pgoff include/linux/mm.h:2480 [inline] vm_mmap_pgoff+0x1b5/0x260 mm/util.c:528 ksys_mmap_pgoff+0x168/0x1e0 mm/mmap.c:1631 do_syscall_64+0xca/0x1c0 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_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0xaf/0x140 mm/page_alloc.c:4961 __vunmap+0x75b/0x890 mm/vmalloc.c:2260 kcov_mmap+0x8c/0x120 kernel/kcov.c:474 call_mmap include/linux/fs.h:1996 [inline] mmap_region+0x110d/0x16f0 mm/mmap.c:1812 do_mmap+0x822/0xd30 mm/mmap.c:1581 do_mmap_pgoff include/linux/mm.h:2480 [inline] vm_mmap_pgoff+0x1b5/0x260 mm/util.c:528 ksys_mmap_pgoff+0x168/0x1e0 mm/mmap.c:1631 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881d4efb080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d4efb100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881d4efb180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881d4efb200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d4efb280: 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 1da3ea067 P4D 1da3ea067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5283 Comm: syz.9.1303 Tainted: G B W 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881dedb0fc0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d4efb1c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffc2b0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4efb1c0 FS: 00007fc3df6db6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001d59ef000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: call_timer_fn+0x36/0x390 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x879/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:__unqueue_futex kernel/futex.c:1545 [inline] RIP: 0010:mark_wake_futex+0x10e/0x1f0 kernel/futex.c:1568 Code: d6 0a 00 09 dd 0f 88 d0 00 00 00 e8 4c d3 0a 00 4d 8d 75 30 4d 89 f4 49 c1 ec 03 43 80 3c 3c 00 74 08 4c 89 f7 e8 62 bd 3a 00 <4d> 8b 3e 4d 85 ff 0f 84 bc 00 00 00 49 8d 5d 18 48 89 d8 48 c1 e8 RSP: 0018:ffff8881f57df9f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff815977b4 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9000314a000 RSI: 000000000000606a RDI: 000000000000606b RBP: 0000000000000003 R08: ffffffff815977a7 R09: ffffed103bdb6bd5 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103c8e2f58 R13: ffff8881e4717a90 R14: ffff8881e4717ac0 R15: dffffc0000000000 futex_wake+0x4f1/0x840 kernel/futex.c:1717 do_futex+0x13fe/0x19f0 kernel/futex.c:3893 __do_sys_futex kernel/futex.c:3949 [inline] __se_sys_futex+0x355/0x470 kernel/futex.c:3917 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7fc3e1071169 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:00007fc3df6db0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fc3e1289fa8 RCX: 00007fc3e1071169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fc3e1289fac RBP: 00007fc3e1289fa0 R08: 00007ffc95bac0b0 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fc3e1289fac R13: 0000000000000000 R14: 00007ffc95afe800 R15: 00007ffc95afe8e8 Modules linked in: CR2: 0000000000000000 ---[ end trace ace2b6c55e6ee69e ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881dedb0fc0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d4efb1c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffc2b0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4efb1c0 FS: 00007fc3df6db6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001d59ef000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 0a 00 or (%rax),%al 2: 09 dd or %ebx,%ebp 4: 0f 88 d0 00 00 00 js 0xda a: e8 4c d3 0a 00 call 0xad35b f: 4d 8d 75 30 lea 0x30(%r13),%r14 13: 4d 89 f4 mov %r14,%r12 16: 49 c1 ec 03 shr $0x3,%r12 1a: 43 80 3c 3c 00 cmpb $0x0,(%r12,%r15,1) 1f: 74 08 je 0x29 21: 4c 89 f7 mov %r14,%rdi 24: e8 62 bd 3a 00 call 0x3abd8b * 29: 4d 8b 3e mov (%r14),%r15 <-- trapping instruction 2c: 4d 85 ff test %r15,%r15 2f: 0f 84 bc 00 00 00 je 0xf1 35: 49 8d 5d 18 lea 0x18(%r13),%rbx 39: 48 89 d8 mov %rbx,%rax 3c: 48 rex.W 3d: c1 .byte 0xc1 3e: e8 .byte 0xe8