================================================================== 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 ffff8881e153f1c8 by task udevd/162 CPU: 1 PID: 162 Comm: udevd 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:get_stack_info+0x17/0x200 arch/x86/kernel/dumpstack_64.c:156 Code: 83 ff 05 77 0b 89 f8 48 8b 04 c5 00 6f a4 84 c3 31 c0 c3 41 57 41 56 41 55 41 54 53 49 89 d7 48 85 ff 74 74 49 89 ce 48 89 f3 <49> 89 fd 48 85 f6 75 08 65 48 8b 1d 29 3d db 7e 4c 89 ef 48 89 de RSP: 0018:ffff8881ec94f510 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1103d929ecd RBX: ffff8881ece3af40 RCX: ffff8881ec94f660 RDX: ffff8881ec94f640 RSI: ffff8881ece3af40 RDI: ffff8881ec94f540 RBP: ffff8881ec94f630 R08: dffffc0000000000 R09: ffff8881ec94f640 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881ec94f660 R13: ffff8881ec94f640 R14: ffff8881ec94f660 R15: ffff8881ec94f640 __unwind_start+0x583/0x890 arch/x86/kernel/unwind_orc.c:660 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xdd/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:690 [inline] kobject_get_path+0xb5/0x1d0 lib/kobject.c:184 kobject_uevent_env+0x286/0x710 lib/kobject_uevent.c:529 kobject_synth_uevent+0x5fa/0xc60 lib/kobject_uevent.c:208 uevent_store+0x20/0x60 drivers/base/core.c:1960 kernfs_fop_write+0x2e2/0x3e0 fs/kernfs/file.c:315 __vfs_write+0x103/0x750 fs/read_write.c:494 vfs_write+0x206/0x4e0 fs/read_write.c:558 ksys_write+0x199/0x2c0 fs/read_write.c:611 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7fe37bfabbf2 Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffc0f07cd38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055fcc048bde0 RCX: 00007fe37bfabbf2 RDX: 0000000000000007 RSI: 000055fcc045fa90 RDI: 000000000000000c RBP: 0000000000000007 R08: 000055fcc045fa90 R09: 0000000000000120 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000007 R13: 000055fcc045fa90 R14: 00007ffc0f07d118 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea0007854fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea0007ae0e08 ffffea0007854f88 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:1994 [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:1994 [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: ffff8881e153f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e153f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881e153f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881e153f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e153f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== ---------------- Code disassembly (best guess): 0: 83 ff 05 cmp $0x5,%edi 3: 77 0b ja 0x10 5: 89 f8 mov %edi,%eax 7: 48 8b 04 c5 00 6f a4 mov -0x7b5b9100(,%rax,8),%rax e: 84 f: c3 ret 10: 31 c0 xor %eax,%eax 12: c3 ret 13: 41 57 push %r15 15: 41 56 push %r14 17: 41 55 push %r13 19: 41 54 push %r12 1b: 53 push %rbx 1c: 49 89 d7 mov %rdx,%r15 1f: 48 85 ff test %rdi,%rdi 22: 74 74 je 0x98 24: 49 89 ce mov %rcx,%r14 27: 48 89 f3 mov %rsi,%rbx * 2a: 49 89 fd mov %rdi,%r13 <-- trapping instruction 2d: 48 85 f6 test %rsi,%rsi 30: 75 08 jne 0x3a 32: 65 48 8b 1d 29 3d db mov %gs:0x7edb3d29(%rip),%rbx # 0x7edb3d63 39: 7e 3a: 4c 89 ef mov %r13,%rdi 3d: 48 89 de mov %rbx,%rsi