================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: use-after-free in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 Write of size 8 at addr ffff8881ec83b1c8 by task syz-executor.4/1156 CPU: 0 PID: 1156 Comm: syz-executor.4 Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #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_add_head include/linux/list.h:814 [inline] enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 __internal_add_timer kernel/time/timer.c:554 [inline] internal_add_timer+0x240/0x430 kernel/time/timer.c:604 __mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065 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:538 [inline] smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:check_memory_region+0x1a0/0x280 mm/kasan/generic.c:191 Code: 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b <41> 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7 RSP: 0018:ffff8881e5297b20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000401 RBX: 0000000000000200 RCX: ffffffff8193fcd6 RDX: 0000000000000001 RSI: 0000000000000200 RDI: ffff8881e5297b60 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed103ca52fac R10: 0000000000000004 R11: dffffc0000000001 R12: 0000000000001000 R13: ffff8881e52e1100 R14: 0000000000000000 R15: 0000000000000004 memset+0x1f/0x40 mm/kasan/common.c:106 save_stack mm/kasan/common.c:67 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1a6/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096 do_sys_open+0x65e/0x810 fs/open.c:1132 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7fb1271a30a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb12651d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb1272d9f80 RCX: 00007fb1271a30a9 RDX: 00000000000026e1 RSI: 0000000020000400 RDI: ffffffffffffff9c RBP: 00007fb127212074 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb1272d9f80 R15: 00007ffe75ba5818 The buggy address belongs to the page: page:ffffea0007b20ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007b20ec8 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 0x140dc0(GFP_USER|__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:4893 __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_large include/linux/slab.h:485 [inline] kmalloc include/linux/slab.h:549 [inline] kzalloc include/linux/slab.h:690 [inline] bpf_check+0xf6/0xb340 kernel/bpf/verifier.c:9561 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849 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:4955 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4961 bpf_check+0x8aaa/0xb340 kernel/bpf/verifier.c:9731 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881ec83b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ec83b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881ec83b180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881ec83b200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ec83b280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== ---------------- Code disassembly (best guess): 0: 4c 89 d5 mov %r10,%rbp 3: 48 8d 5d 07 lea 0x7(%rbp),%rbx 7: 48 85 ed test %rbp,%rbp a: 48 0f 49 dd cmovns %rbp,%rbx e: 48 83 e3 f8 and $0xfffffffffffffff8,%rbx 12: 48 29 dd sub %rbx,%rbp 15: 74 12 je 0x29 17: 41 80 39 00 cmpb $0x0,(%r9) 1b: 0f 85 a2 00 00 00 jne 0xc3 21: 49 ff c1 inc %r9 24: 48 ff cd dec %rbp 27: 75 ee jne 0x17 29: 5b pop %rbx * 2a: 41 5e pop %r14 <-- trapping instruction 2c: 41 5f pop %r15 2e: 5d pop %rbp 2f: c3 ret 30: 45 84 f6 test %r14b,%r14b 33: 75 61 jne 0x96 35: 41 f7 c6 00 ff 00 00 test $0xff00,%r14d 3c: 75 5d jne 0x9b 3e: 41 rex.B 3f: f7 .byte 0xf7