In the Linux kernel, the following vulnerability has been resolved: tracing/synthetic: Fix races on freeing last_cmd Currently, the "last_cmd" variable can be accessed by multiple processes asynchronously when multiple users manipulate synthetic_events node at the same time, it could lead to use-after-free or double-free. This patch add "lastcmd_mutex" to prevent "last_cmd" from being accessed asynchronously. ================================================================ It's easy to reproduce in the KASAN environment by running the two scripts below in different shells. script 1: while : do echo -n -e '\x88' > /sys/kernel/tracing/synthetic_events done script 2: while : do echo -n -e '\xb0' > /sys/kernel/tracing/synthetic_events done ================================================================ double-free scenario: process A process B ------------------- --------------- 1.kstrdup last_cmd 2.free last_cmd 3.free last_cmd(double-free) ================================================================ use-after-free scenario: process A process B ------------------- --------------- 1.kstrdup last_cmd 2.free last_cmd 3.tracing_log_err(use-after-free) ================================================================ Appendix 1. KASAN report double-free: BUG: KASAN: double-free in kfree+0xdc/0x1d4 Free of addr ***** by task sh/4879 Call trace: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x60/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Allocated by task 4879: ... kstrdup+0x5c/0x98 create_or_delete_synth_event+0x6c/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Freed by task 5464: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x60/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... ================================================================ Appendix 2. KASAN report use-after-free: BUG: KASAN: use-after-free in strlen+0x5c/0x7c Read of size 1 at addr ***** by task sh/5483 sh: CPU: 7 PID: 5483 Comm: sh ... __asan_report_load1_noabort+0x34/0x44 strlen+0x5c/0x7c tracing_log_err+0x60/0x444 create_or_delete_synth_event+0xc4/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Allocated by task 5483: ... kstrdup+0x5c/0x98 create_or_delete_synth_event+0x80/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Freed by task 5480: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x74/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ...
総合評価: CVE-2023-53478 は低リスク（19.2/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.10%、1 パーセンタイル） 推奨対応: 総合リスクは低く緊急対応は不要です。通常の保守サイクルでパッチを適用し、CVSS / EPSS が上昇したら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 | 0.02% | 0.10% | +0.08% |
| 2 | 2025-10-01 | — | 0.02% | — |
EPSS の全履歴 （全 2 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 |
|---|---|---|---|---|---|---|
| 4.7 | 3.1 | MEDIUM |
|
1.0 | 3.6 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2023-53478 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2023-53478 |
redhat
|
— | — | https://access.redhat.com/security/cve/CVE-2023-53478 |
suse
|
medium | CVE-2023-53478 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 276 product×package rows across 54 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (54 product lines)): Known Not Affected 276. | https://www.suse.com/security/cve/CVE-2023-53478/ |
ubuntu
|
medium | CVE-2023-53478 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 162, released 88, needed 75, not-affected 72. | https://ubuntu.com/security/CVE-2023-53478 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 5.18, < 6.1.24 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.2, < 6.2.11 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 6.3 | cpe:2.3:o:linux:linux_kernel:6.3:rc1:*:*:*:*:*:* |
| linux | linux_kernel | 6.3 | cpe:2.3:o:linux:linux_kernel:6.3:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 6.3 | cpe:2.3:o:linux:linux_kernel:6.3:rc3:*:*:*:*:*:* |
| linux | linux_kernel | 6.3 | cpe:2.3:o:linux:linux_kernel:6.3:rc4:*:*:*:*:*:* |
| linux | linux_kernel | 6.3 | cpe:2.3:o:linux:linux_kernel:6.3:rc5:*:*:*:*:*:* |