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KASAN: invalid-access Write in do_bad_area

Status: upstream: reported C repro on 2025/10/05 10:08
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+997752115a851cb0cf36@syzkaller.appspotmail.com
Fix commit: 007f5da43b3d mm/kasan: fix incorrect unpoisoning in vrealloc for KASAN
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu2-riscv64 ci-upstream-bpf-next-kasan-gce ci2-upstream-usb]
First crash: 102d, last: 12d
▶ ▼ Discussions (9)
Title Replies (including bot) Last reply
KASAN vs realloc 8 (8) 2026/01/09 20:05
[PATCH v5 0/3] kasan: vmalloc: Fixes for the percpu allocator and vrealloc 2 (2) 2025/12/17 13:50
[PATCH v4 0/3] kasan: vmalloc: Fixes for the percpu allocator and vrealloc 2 (2) 2025/12/05 14:59
[PATCH v3 0/3] kasan: vmalloc: Fixes for the percpu allocator and vrealloc 3 (3) 2025/12/05 01:08
Re: [PATCH v1] mm/kasan: Fix incorrect unpoisoning in vrealloc for KASAN 5 (5) 2025/12/04 15:35
Re: [PATCH v1] mm/kasan: Fix incorrect unpoisoning in vrealloc for KASAN 1 (1) 2025/12/03 07:30
[PATCH v1] mm/kasan: Fix incorrect unpoisoning in vrealloc for KASAN 5 (5) 2025/12/03 02:05
[syzbot] Monthly bpf report (Nov 2025) 0 (1) 2025/11/05 08:25
[syzbot] [bpf?] KASAN: invalid-access Write in do_bad_area 1 (3) 2025/10/07 18:35

Sample crash report:
==================================================================
BUG: KASAN: invalid-access in __memcpy+0xc/0x54 arch/arm64/lib/memcpy.S:250
Write at addr f6ff800083afd77f by task syz.2.17/3579
Pointer tag: [f6], memory tag: [fe]

CPU: 0 UID: 0 PID: 3579 Comm: syz.2.17 Not tainted syzkaller #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Call trace:
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x78/0x90 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x108/0x61c mm/kasan/report.c:482
 kasan_report+0x88/0xac mm/kasan/report.c:595
 report_tag_fault arch/arm64/mm/fault.c:330 [inline]
 do_tag_recovery arch/arm64/mm/fault.c:342 [inline]
 __do_kernel_fault+0x170/0x1c8 arch/arm64/mm/fault.c:384
 do_bad_area+0x68/0x78 arch/arm64/mm/fault.c:484
 do_tag_check_fault+0x34/0x44 arch/arm64/mm/fault.c:857
 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:933
 el1_abort+0x44/0x68 arch/arm64/kernel/entry-common.c:303
 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:437
 el1h_64_sync+0x6c/0x70 arch/arm64/kernel/entry.S:591
 __memcpy+0xc/0x54 arch/arm64/lib/memcpy.S:250 (P)
 do_misc_fixups+0xe30/0x1afc kernel/bpf/verifier.c:22918
 bpf_check+0x1384/0x293c kernel/bpf/verifier.c:25294
 bpf_prog_load+0x63c/0xd40 kernel/bpf/syscall.c:3088
 __sys_bpf+0x2e0/0x1a88 kernel/bpf/syscall.c:6164
 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
 __arm64_sys_bpf+0x24/0x34 kernel/bpf/syscall.c:6272
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
 el0_svc+0x34/0x128 arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:596

The buggy address belongs to a 1-page vmalloc region starting at 0xf6ff800083afd000 allocated at bpf_check+0x8c/0x293c kernel/bpf/verifier.c:25134
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43b01
flags: 0x1ffe40000000000(node=0|zone=0|lastcpupid=0x7ff|kasantag=0x9)
raw: 01ffe40000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff800083afd500: f6 f6 f6 f6 fe fe fe fe fe fe fe fe fe fe fe fe
 ffff800083afd600: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>ffff800083afd700: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                                        ^
 ffff800083afd800: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff800083afd900: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
==================================================================

Crashes (34838):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/11 06:15 upstream 0048fbb4011e 48b27acc .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/10/07 14:58 upstream c746c3b51698 8ef35d49 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 22:50 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 22:38 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 22:26 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 22:14 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 22:01 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 21:28 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 21:09 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 20:57 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 20:45 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 20:34 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 20:24 upstream 7839932417dd a938fefb .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 08:47 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 07:49 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 06:40 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 06:24 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 06:07 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 05:57 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 05:46 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/29 05:40 upstream c875a6c32467 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 17:04 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 16:48 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 16:30 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 16:11 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 15:43 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 15:21 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 15:02 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 14:10 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 14:02 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 12:50 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 12:33 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 12:07 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 11:56 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 11:48 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 11:33 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 11:13 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 10:56 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 10:45 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 10:31 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/28 10:22 upstream d26143bb38e2 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/27 22:02 upstream c53f467229a7 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/27 21:39 upstream c53f467229a7 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/12/27 21:17 upstream c53f467229a7 5dc09de1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/10/05 05:45 upstream cbf33b8e0b36 49379ee0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
2025/10/01 10:07 upstream 50c19e20ed2e 3af39644 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte KASAN: invalid-access Write in do_bad_area
* Struck through repros no longer work on HEAD.