GHSA-34r5-4vr6-q5h6 · 深刻度： high — In the Linux kernel, the following vulnerability has been resolved: bpf: Do mark_chain_precision...
In the Linux kernel, the following vulnerability has been resolved: bpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO 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.
総合評価: CVE-2022-49961 は低リスク（32.8/100）。CVSS 深刻度は高。悪用される可能性が高い（EPSS 0.22%、12 パーセンタイル） 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.08% | 0.22% | +0.14% |
| 2 | 2026-04-14 | 0.02% | 0.08% | +0.06% |
| 3 | 2025-06-18 | — | 0.02% | — |
EPSS の全履歴 （全 3 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 7.1 | 3.1 | HIGH |
|
1.8 | 5.2 | [email protected] |
GHSA-34r5-4vr6-q5h6 · 深刻度： high — In the Linux kernel, the following vulnerability has been resolved: bpf: Do mark_chain_precision...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2022-49961 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. | https://security-tracker.debian.org/tracker/CVE-2022-49961 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2022-49961 |
suse
|
medium | CVE-2022-49961 severity moderate: SUSE including 52 source package names (bpftool-7.0.0-284.11.1.el9_2, cluster-md-kmp-default, …), 169 product×package rows across 31 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Liberty Linux 9, … (31 product lines)): Known Not Affected 142, Fixed 27. | https://www.suse.com/security/cve/CVE-2022-49961/ |
ubuntu
|
medium | CVE-2022-49961 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 147, not-affected 134, released 92, needed 33. | https://ubuntu.com/security/CVE-2022-49961 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 5.8, < 5.19.8 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 6.0 | cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:* |
| linux | linux_kernel | 6.0 | cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 6.0 | cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:* |