high 7.1

CVE-2022-49961 json

bpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO

published 2025-06-18 16 mo ago modified 2026-11-05 3 d ago also EUVD-2022-55243

cvss: 7.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

Precision markers need to be propagated whenever we have an ARG_CONST_* style argument, as the verifier cannot consider imprecise scalars to be equivalent for the purposes of states_equal check when such arguments refine the return value (in this case, set mem_size for PTR_TO_MEM). The resultant mem_size for the R0 is derived from the constant value, and if the verifier incorrectly prunes states considering them equivalent where such arguments exist (by seeing that both registers have reg->precise as false in regsafe), we can end up with invalid programs passing the verifier which can do access beyond what should have been the correct mem_size in that explored state.

To show a concrete example of the problem:

0000000000000000 <prog>: 0: r2 = *(u32 *)(r1 + 80) 1: r1 = *(u32 *)(r1 + 76) 2: r3 = r1 3: r3 += 4 4: if r3 > r2 goto +18 <LBB5_5> 5: w2 = 0 6: *(u32 *)(r1 + 0) = r2 7: r1 = *(u32 *)(r1 + 0) 8: r2 = 1 9: if w1 == 0 goto +1 <LBB5_3> 10: r2 = -1

0000000000000058 <LBB5_3>: 11: r1 = 0 ll 13: r3 = 0 14: call bpf_ringbuf_reserve 15: if r0 == 0 goto +7 <LBB5_5> 16: r1 = r0 17: r1 += 16777215 18: w2 = 0 19: *(u8 *)(r1 + 0) = r2 20: r1 = r0 21: r2 = 0 22: call bpf_ringbuf_submit

00000000000000b8 <LBB5_5>: 23: w0 = 0 24: exit

For the first case, the single line execution's exploration will prune the search at insn 14 for the branch insn 9's second leg as it will be verified first using r2 = -1 (UINT_MAX), while as w1 at insn 9 will always be 0 so at runtime we don't get error for being greater than UINT_MAX/4 from bpf_ringbuf_reserve. The verifier during regsafe just sees reg->precise as false for both r2 registers in both states, hence considers them equal for purposes of states_equal.

If we propagated precise markers using the backtracking support, we would use the precise marking to then ensure that old r2 (UINT_MAX) was within the new r2 (1) and this would never be true, so the verification would rightfully fail.

The end result is that the out of bounds access at instruction 19 would be permitted without this fix.

Note that reg->precise is always set to true when user does not have CAP_BPF (or when subprog count is greater than 1 (i.e. use of any static or global functions)), hence this is only a problem when precision marks need to be explicitly propagated (i.e. privileged users with CAP_BPF).

A simplified test case has been included in the next patch to prevent future regressions.

Patch / fix

fixed in 1 distros 3 links 4

Linux Linux 5.10.273, 5.15.209, 5.19.8, 6.0

debian ubuntu red hat

linux Debian 14, Debian 13, Debian 12 5.19.11-1

debian advisories DEBIAN-CVE-2022-49961

linux Ubuntu 22.04 LTS 5.15.0-186.196
linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
linux-gke Ubuntu 22.04 LTS 5.15.0-1108.114
linux-ibm Ubuntu 22.04 LTS 5.15.0-1106.110
linux-kvm Ubuntu 22.04 LTS 5.15.0-1104.109
linux-azure Ubuntu 22.04 LTS 5.15.0-1117.126
linux-gkeop Ubuntu 22.04 LTS 5.15.0-1095.103

ubuntu advisories UBUNTU-CVE-2022-49961

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel RHEL 9 5.14.0-284.11.1.el9_2
perf RHEL 9 5.14.0-284.11.1.el9_2
rtla RHEL 9 5.14.0-284.11.1.el9_2
bpftool RHEL 9 7.0.0-284.11.1.el9_2
kernel-64k RHEL 9 5.14.0-284.11.1.el9_2
kernel-core RHEL 9 5.14.0-284.11.1.el9_2
kernel-tools RHEL 9 5.14.0-284.11.1.el9_2
python3-perf RHEL 9 5.14.0-284.11.1.el9_2

red hat advisories RHSA-2023:2458

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49961 updated 2026-11-05 cvss 5.5

kernel: bpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO

Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
affected: no fix available “Fix deferred”
Red Hat Enterprise Linux AppStream (v. 9) perf 5.14.0-284.11.1.el9_2, rtla 5.14.0-284.11.1.el9_2, kernel-devel-matched 5.14.0-284.11.1.el9_2, kernel-64k-devel-matched 5.14.0-284.11.1.el9_2, kernel-debug-devel-matched 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, +5 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.0.0-284.11.1.el9_2, kernel 5.14.0-284.11.1.el9_2, kernel-64k 5.14.0-284.11.1.el9_2, kernel-core 5.14.0-284.11.1.el9_2, kernel-tools 5.14.0-284.11.1.el9_2, python3-perf 5.14.0-284.11.1.el9_2, +28 more Red Hat Enterprise Linux CRB (v. 9) kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.11.1.el9_2
fixed: vendor fix RHSA-2023:2458
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 d ago (2026-11-05)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

Linux Linux

Classification

Weakness

CWE-125 Out-of-bounds Read

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2022-49961
NVD CVE-2022-49961

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary