In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix BPF_F_CPU validation for sparse CPU IDs
BPF_F_CPU stores the target CPU ID in the upper 32 bits of the map
operation flags. bpf_map_check_op_flags() currently compares that ID
with num_possible_cpus(), which is the number of possible CPUs rather
than a bound on CPU IDs.
On an arm64 QEMU guest with a CPU device-tree hole, the possible CPU
mask was 0,2-3. A userspace program using raw bpf() syscalls creates
a BPF_MAP_TYPE_PERCPU_ARRAY and performs update and lookup operations
for each CPU by setting BPF_F_CPU and the CPU ID in the flags.
With the old check, CPU 1 is incorrectly accepted while valid CPU 3 is
rejected with -ERANGE. The CPU 1 update then reaches the per-CPU map
access path and triggers:
Unable to handle kernel paging request at virtual address ...
pc : __pi_memcpy_generic+0x5c/0x22c
lr : bpf_percpu_array_update+0x2dc/0x2e8
Call trace:
__pi_memcpy_generic
bpf_map_update_value
map_update_elem
__sys_bpf
Check the CPU ID against nr_cpu_ids and cpu_possible() instead. This
rejects CPU IDs outside the valid range and CPUs absent from the
possible mask, while allowing valid sparse CPU IDs.
References
Configurations
Configuration 1 (hide)
|
History
21 Oct 2026, 20:24
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:linux:linux_kernel:7.3:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| References | () https://git.kernel.org/stable/c/bdc5941f6eeef90b76a07fd8ca38ac1933ba2195 - Patch | |
| References | () https://git.kernel.org/stable/c/ed54bf564ac52699cf4def3d0c2125d493e756f9 - Patch |
25 Sep 2026, 15:18
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.0 |
25 Sep 2026, 11:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-25 11:17
Updated : 2026-10-21 20:24
NVD link : CVE-2026-98150
Mitre link : CVE-2026-98150
CVE.ORG link : CVE-2026-98150
JSON object : View
Products Affected
linux
- linux_kernel
CWE
