CVE-2022-50168
CVE-2022-50168 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- EPSS exploit prediction: 0% (11th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2022-55433
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: bpf, x86: fix freeing of not-finalized bpf_prog_pack syzbot reported a few issues with bpf_prog_pack [1], [2]. This only happens with multiple subprogs. In jit_subprogs(), we first call bpf_int_jit_compile() on each sub program. And then, we call it on each sub program again. jit_data is not freed in the first call of bpf_int_jit_compile(). Similarly we don't call bpf_jit_binary_pack_finalize() in the first call of bpf_int_jit_compile(). If bpf_int_jit_compile() failed for one sub program, we will call bpf_jit_binary_pack_finalize() for this sub program. However, we don't have a chance to call it for other sub programs. Then we will hit "goto out_free" in jit_subprogs(), and call bpf_jit_free on some subprograms that haven't got bpf_jit_binary_pack_finalize() yet. At this point, bpf_jit_binary_pack_free() is called and the whole 2MB page is freed erroneously. Fix this with a custom bpf_jit_free() for x86_64, which calls bpf_jit_binary_pack_finalize() if necessary. Also, with custom bpf_jit_free(), bpf_prog_aux->use_bpf_prog_pack is not needed any more, remove it. [1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f [2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445
Frequently asked questions
- What is CVE-2022-50168?
- In the Linux kernel, the following vulnerability has been resolved: bpf, x86: fix freeing of not-finalized bpf_prog_pack syzbot reported a few issues with bpf_prog_pack [1], [2]. This only happens with multiple subprogs. In jit_subprogs(), we first call bpf_int_jit_compile() on each sub program. And then, we call it on each sub program again. jit_data is not freed in the first call of bpf_int_jit_compile(). Similarly we don't call bpf_jit_binary_pack_finalize() in the first call of bpf_int_jit_compile(). If bpf_int_jit_compile() failed for one sub program, we will call bpf_jit_binary_pack_finalize() for this sub program. However, we don't have a chance to call it for other sub programs. Then we will hit "goto out_free" in jit_subprogs(), and call bpf_jit_free on some subprograms that haven't got bpf_jit_binary_pack_finalize() yet. At this point, bpf_jit_binary_pack_free() is called and the whole 2MB page is freed erroneously. Fix this with a custom bpf_jit_free() for x86_64, which calls bpf_jit_binary_pack_finalize() if necessary. Also, with custom bpf_jit_free(), bpf_prog_aux->use_bpf_prog_pack is not needed any more, remove it. [1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f [2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445
- How severe is CVE-2022-50168?
- CVE-2022-50168 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2022-50168 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-50168?
- CVE-2022-50168 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2022-50168?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2022-50168 have an EU (EUVD) identifier?
- Yes. CVE-2022-50168 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-55433.
- When was CVE-2022-50168 published?
- CVE-2022-50168 was published on 2025-06-18 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/1d5f82d9dd477d5c66e0214a68c3e4f308eadd6d
- https://git.kernel.org/stable/c/60e66074812dde9cde3d99cdd3caa9e40f1a4516
- https://git.kernel.org/stable/c/f91ce608a79c0db3e72bd63c23e011a9ebc31505
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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