Linux Kernel up to 7.2.6/7.3-rc1 BPF bpf_map_check_op_flags out-of-bounds write

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 7.2.6/7.3-rc1. Impacted is the function bpf_map_check_op_flags of the component BPF. The manipulation results in out-of-bounds write. This vulnerability is identified as CVE-2026-98150. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.2.6/7.3-rc1. Affected is the function bpf_map_check_op_flags of the component BPF. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98150 since 09/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation needs additional levels of successful authentication. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch bdc5941f6eeef90b76a07fd8ca38ac1933ba2195/ed54bf564ac52699cf4def3d0c2125d493e756f9 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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