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KASAN: use-after-free Read in acpi_ns_get_attached_object

Status: moderation: reported on 2026/05/09 17:34
Subsystems: acpica
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+44e1f517a61cb01f8ca2@syzkaller.appspotmail.com
First crash: 11d, last: 11d
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
78e623ab-09e0-4c70-871f-065e70944f8c assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: use-after-free Read in acpi_ns_get_attached_object 2026/05/16 01:52 2026/05/16 01:52 2026/05/16 02:37 efdaf0f9b8bfc56ea6d17bea15a64f4591cc712d
40a14ce9-672c-4f3f-97d3-33874b010879 moderation Actionable: ✅ ❓ KASAN: use-after-free Read in acpi_ns_get_attached_object 2026/05/10 04:06 2026/05/10 04:06 2026/05/10 04:34 29233ece713919081e9069c2a18be92526041f39

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in acpi_ns_get_attached_object+0x148/0x1b0 drivers/acpi/acpica/nsobject.c:258
Read of size 1 at addr ffff8880216de8f8 by task syz.2.1126/11381

CPU: 0 UID: 0 PID: 11381 Comm: syz.2.1126 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
 acpi_ns_get_attached_object+0x148/0x1b0 drivers/acpi/acpica/nsobject.c:258
 acpi_ns_evaluate+0x158/0x1670 drivers/acpi/acpica/nseval.c:83
 acpi_ut_evaluate_object+0xf7/0x610 drivers/acpi/acpica/uteval.c:60
 acpi_rs_get_prt_method_data+0xa0/0x150 drivers/acpi/acpica/rsutils.c:446
 acpi_get_irq_routing_table+0xb8/0x140 drivers/acpi/acpica/rsxface.c:137
 acpi_pci_irq_find_prt_entry+0x179/0xdd0 drivers/acpi/pci_irq.c:215
 acpi_pci_irq_lookup+0x8e/0x6b0 drivers/acpi/pci_irq.c:299
 acpi_pci_irq_enable+0x1f5/0x6f0 drivers/acpi/pci_irq.c:414
 pcibios_enable_device+0xb6/0xe0 arch/x86/pci/common.c:699
 do_pci_enable_device+0x21f/0x4a0 drivers/pci/pci.c:2000
 pci_enable_device_flags+0x27c/0x370 drivers/pci/pci.c:2091
 enable_store+0x1e1/0x260 drivers/pci/pci-sysfs.c:341
 dev_attr_store+0x58/0x80 drivers/base/core.c:2437
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:688
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b35f9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7b36df4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7b36215fa0 RCX: 00007f7b35f9cdd9
RDX: 0000000000000081 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007f7b36032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b36216038 R14: 00007f7b36215fa0 R15: 00007ffcfd654598
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x4b pfn:0x216de
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0000ab0808 ffffea0000a7ef48 0000000000000000
raw: 000000000000004b 0000000000000000 00000000f0000000 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 0x100cc2(GFP_HIGHUSER), pid 10859, tgid 10858 (syz.1.1050), ts 363170141420, free_ts 364039095485
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
 alloc_pages_noprof+0x1a/0x160 mm/mempolicy.c:2581
 kimage_alloc_pages+0x72/0x380 kernel/kexec_core.c:284
 kimage_alloc_page+0x232/0x910 kernel/kexec_core.c:686
 kimage_load_normal_segment kernel/kexec_core.c:825 [inline]
 kimage_load_segment+0x507/0xde0 kernel/kexec_core.c:943
 do_kexec_load+0x58d/0x810 kernel/kexec.c:155
 __do_sys_kexec_load kernel/kexec.c:261 [inline]
 __se_sys_kexec_load kernel/kexec.c:242 [inline]
 __x64_sys_kexec_load+0x1bf/0x230 kernel/kexec.c:242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 10859 tgid 10858 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943
 kimage_free_entry kernel/kexec_core.c:554 [inline]
 kimage_free+0x245/0x5a0 kernel/kexec_core.c:601
 do_kexec_load+0x34c/0x810 kernel/kexec.c:175
 __do_sys_kexec_load kernel/kexec.c:261 [inline]
 __se_sys_kexec_load kernel/kexec.c:242 [inline]
 __x64_sys_kexec_load+0x1bf/0x230 kernel/kexec.c:242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880216de780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880216de800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880216de880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff8880216de900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880216de980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/05 17:23 upstream a293ec25d59d 114c483e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: use-after-free Read in acpi_ns_get_attached_object
* Struck through repros no longer work on HEAD.