================================================================== 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 ffff8881e0e7b1c8 by task syz.1.1860/6095 CPU: 0 PID: 6095 Comm: syz.1.1860 Tainted: G W 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:check_kcov_mode kernel/kcov.c:153 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x50 kernel/kcov.c:187 Code: 96 d1 85 e8 6b f2 2d 00 5d c3 00 00 90 90 00 00 90 90 00 55 48 89 e5 48 8b 45 08 65 48 8b 0d 90 0e a3 7e 65 8b 15 95 0e a3 7e c2 00 01 1f 00 74 02 5d c3 8b 91 00 0a 00 00 83 fa 02 75 f3 48 RSP: 0018:ffff8881e830f5d0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81846e59 RBX: 00007f2882b6e000 RCX: ffff8881cb4daf40 RDX: 0000000080000001 RSI: 000000000023ffff RDI: 00000000001d6650 RBP: ffff8881e830f5d0 R08: dffffc0000000000 R09: ffffed103969b5e9 R10: ffffed103969b5e9 R11: 1ffff1103969b5e8 R12: 00000000001d6650 R13: 000000000023ffff R14: 80000001d6650007 R15: ffff8881df76e378 vm_normal_page+0x99/0x1f0 mm/memory.c:658 zap_pte_range mm/memory.c:1078 [inline] zap_pmd_range mm/memory.c:1222 [inline] zap_pud_range mm/memory.c:1251 [inline] zap_p4d_range mm/memory.c:1272 [inline] unmap_page_range+0xaf6/0x1b20 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x245/0x340 mm/memory.c:1370 exit_mmap+0x2bb/0x520 mm/mmap.c:3191 __mmput+0x92/0x2e0 kernel/fork.c:1101 mmput+0x47/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:538 [inline] do_exit+0x99f/0x2660 kernel/exit.c:848 do_group_exit+0x13e/0x300 kernel/exit.c:984 get_signal+0xdee/0x13d0 kernel/signal.c:2738 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f288416e969 Code: Bad RIP value. RSP: 002b:00007f28827d70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f2884395fa8 RCX: 00007f288416e969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2884395fa8 RBP: 00007f2884395fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2884395fac R13: 0000000000000000 R14: 00007ffecae98620 R15: 00007ffecae98708 The buggy address belongs to the page: page:ffffea0007839ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea0007839e88 ffffea00071c2e08 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+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] __vmalloc_area_node mm/vmalloc.c:-1 [inline] __vmalloc_node_range+0x36a/0x6e0 mm/vmalloc.c:2499 vmalloc_user+0x73/0x80 mm/vmalloc.c:2629 kcov_mmap+0x2b/0x120 kernel/kcov.c:450 call_mmap include/linux/fs.h:1996 [inline] mmap_region+0x101b/0x15a0 mm/mmap.c:1812 do_mmap+0x826/0xd90 mm/mmap.c:1581 do_mmap_pgoff include/linux/mm.h:2480 [inline] vm_mmap_pgoff+0x195/0x230 mm/util.c:528 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1631 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:97 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:88 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:88 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_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x2a9/0x3a0 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4954 [inline] __free_pages+0xaa/0x110 mm/page_alloc.c:4962 __vunmap+0x76a/0x8a0 mm/vmalloc.c:2260 __vfree mm/vmalloc.c:2308 [inline] vfree+0x61/0x90 mm/vmalloc.c:2338 kcov_mmap+0x8c/0x120 kernel/kcov.c:474 call_mmap include/linux/fs.h:1996 [inline] mmap_region+0x101b/0x15a0 mm/mmap.c:1812 do_mmap+0x826/0xd90 mm/mmap.c:1581 do_mmap_pgoff include/linux/mm.h:2480 [inline] vm_mmap_pgoff+0x195/0x230 mm/util.c:528 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1631 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:97 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:88 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:88 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881e0e7b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e0e7b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881e0e7b180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881e0e7b200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e0e7b280: 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 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 6095 Comm: syz.1.1860 Tainted: G B W 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: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881cb4daf40 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e0e7b1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffe770 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e0e7b1c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0 DR0: 0000000000000000 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: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:check_kcov_mode kernel/kcov.c:153 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x50 kernel/kcov.c:187 Code: 96 d1 85 e8 6b f2 2d 00 5d c3 00 00 90 90 00 00 90 90 00 55 48 89 e5 48 8b 45 08 65 48 8b 0d 90 0e a3 7e 65 8b 15 95 0e a3 7e c2 00 01 1f 00 74 02 5d c3 8b 91 00 0a 00 00 83 fa 02 75 f3 48 RSP: 0018:ffff8881e830f5d0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81846e59 RBX: 00007f2882b6e000 RCX: ffff8881cb4daf40 RDX: 0000000080000001 RSI: 000000000023ffff RDI: 00000000001d6650 RBP: ffff8881e830f5d0 R08: dffffc0000000000 R09: ffffed103969b5e9 R10: ffffed103969b5e9 R11: 1ffff1103969b5e8 R12: 00000000001d6650 R13: 000000000023ffff R14: 80000001d6650007 R15: ffff8881df76e378 vm_normal_page+0x99/0x1f0 mm/memory.c:658 zap_pte_range mm/memory.c:1078 [inline] zap_pmd_range mm/memory.c:1222 [inline] zap_pud_range mm/memory.c:1251 [inline] zap_p4d_range mm/memory.c:1272 [inline] unmap_page_range+0xaf6/0x1b20 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x245/0x340 mm/memory.c:1370 exit_mmap+0x2bb/0x520 mm/mmap.c:3191 __mmput+0x92/0x2e0 kernel/fork.c:1101 mmput+0x47/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:538 [inline] do_exit+0x99f/0x2660 kernel/exit.c:848 do_group_exit+0x13e/0x300 kernel/exit.c:984 get_signal+0xdee/0x13d0 kernel/signal.c:2738 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f288416e969 Code: Bad RIP value. RSP: 002b:00007f28827d70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f2884395fa8 RCX: 00007f288416e969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2884395fa8 RBP: 00007f2884395fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2884395fac R13: 0000000000000000 R14: 00007ffecae98620 R15: 00007ffecae98708 Modules linked in: CR2: 0000000000000000 ---[ end trace f88a7515e183ee45 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881cb4daf40 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e0e7b1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffe770 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e0e7b1c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 96 xchg %eax,%esi 1: d1 85 e8 6b f2 2d roll 0x2df26be8(%rbp) 7: 00 5d c3 add %bl,-0x3d(%rbp) a: 00 00 add %al,(%rax) c: 90 nop d: 90 nop e: 00 00 add %al,(%rax) 10: 90 nop 11: 90 nop 12: 00 55 48 add %dl,0x48(%rbp) 15: 89 e5 mov %esp,%ebp 17: 48 8b 45 08 mov 0x8(%rbp),%rax 1b: 65 48 8b 0d 90 0e a3 mov %gs:0x7ea30e90(%rip),%rcx # 0x7ea30eb3 22: 7e 23: 65 8b 15 95 0e a3 7e mov %gs:0x7ea30e95(%rip),%edx # 0x7ea30ebf * 2a: f7 c2 00 01 1f 00 test $0x1f0100,%edx <-- trapping instruction 30: 74 02 je 0x34 32: 5d pop %rbp 33: c3 ret 34: 8b 91 00 0a 00 00 mov 0xa00(%rcx),%edx 3a: 83 fa 02 cmp $0x2,%edx 3d: 75 f3 jne 0x32 3f: 48 rex.W