================================================================== 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:1452 [inline] BUG: KASAN: use-after-free in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787 Write of size 8 at addr ffff8881e55031c8 by task syz-executor.3/1915 CPU: 0 PID: 1915 Comm: syz-executor.3 Not tainted 5.4.268-syzkaller-00001-g8322246edffa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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:1452 [inline] __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1086 The buggy address belongs to the page: page:ffffea00079540c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007954088 0000000000000000 raw: 0000000000000000 0000000000100000 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 0x146dc0(GFP_USER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__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+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:4891 __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+0x2a/0x100 mm/slab_common.c:1358 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x7e/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvzalloc include/linux/mm.h:769 [inline] alloc_netdev_mqs+0x85/0xc70 net/core/dev.c:9610 tun_set_iff+0x51f/0xdc0 drivers/net/tun.c:2887 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3181 do_vfs_ioctl+0x742/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 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_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4959 device_release+0x6b/0x190 drivers/base/core.c:1776 kobject_cleanup lib/kobject.c:716 [inline] kobject_release lib/kobject.c:747 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e6/0x2f0 lib/kobject.c:764 netdev_run_todo+0xc44/0xdf0 net/core/dev.c:9469 tun_detach drivers/net/tun.c:765 [inline] tun_chr_close+0xc1/0x130 drivers/net/tun.c:3557 __fput+0x262/0x680 fs/file_table.c:281 task_work_run+0x140/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881e5503080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e5503100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881e5503180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881e5503200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e5503280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1915 Comm: syz-executor.3 Tainted: G B 5.4.268-syzkaller-00001-g8322246edffa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:__hlist_del include/linux/list.h:791 [inline] RIP: 0010:detach_timer kernel/time/timer.c:824 [inline] RIP: 0010:expire_timers kernel/time/timer.c:1452 [inline] RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1787 Code: 89 e7 e8 e3 4b 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 45 68 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 b2 4b 3f 00 4d 89 65 00 eb 05 e8 17 RSP: 0018:ffff8881f6e09dc0 EFLAGS: 00010802 RAX: 1bd5a00000000025 RBX: 1ffff1103caa0639 RCX: dffffc0000000000 RDX: 0000000000000103 RSI: 0000000000000008 RDI: ffff8881e55031c8 RBP: ffff8881f6e09f28 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6e09e80 R13: dead00000000012a R14: 1ffff1103caa0638 R15: ffff8881e55031c8 FS: 00007fe7c913a6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020d36000 CR3: 00000001f0580000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1086 Modules linked in: ---[ end trace 0d815f397cf43fe4 ]--- RIP: 0010:__hlist_del include/linux/list.h:791 [inline] RIP: 0010:detach_timer kernel/time/timer.c:824 [inline] RIP: 0010:expire_timers kernel/time/timer.c:1452 [inline] RIP: 0010:__run_timers+0x7b0/0xbe0 kernel/time/timer.c:1787 Code: 89 e7 e8 e3 4b 3f 00 4d 89 2c 24 4d 85 ed 74 2e e8 45 68 0f 00 49 83 c5 08 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 b2 4b 3f 00 4d 89 65 00 eb 05 e8 17 RSP: 0018:ffff8881f6e09dc0 EFLAGS: 00010802 RAX: 1bd5a00000000025 RBX: 1ffff1103caa0639 RCX: dffffc0000000000 RDX: 0000000000000103 RSI: 0000000000000008 RDI: ffff8881e55031c8 RBP: ffff8881f6e09f28 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff8881f6e09e80 R13: dead00000000012a R14: 1ffff1103caa0638 R15: ffff8881e55031c8 FS: 00007fe7c913a6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020d36000 CR3: 00000001f0580000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 89 e7 mov %esp,%edi 2: e8 e3 4b 3f 00 call 0x3f4bea 7: 4d 89 2c 24 mov %r13,(%r12) b: 4d 85 ed test %r13,%r13 e: 74 2e je 0x3e 10: e8 45 68 0f 00 call 0xf685a 15: 49 83 c5 08 add $0x8,%r13 19: 4c 89 e8 mov %r13,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 ef mov %r13,%rdi 33: e8 b2 4b 3f 00 call 0x3f4bea 38: 4d 89 65 00 mov %r12,0x0(%r13) 3c: eb 05 jmp 0x43 3e: e8 .byte 0xe8 3f: 17 (bad)