| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21889: perf/core: Add RCU read lock protection to perf_iterate_ctx() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| perf/core: Add RCU read lock protection to perf_iterate_ctx() |
| |
| The perf_iterate_ctx() function performs RCU list traversal but |
| currently lacks RCU read lock protection. This causes lockdep warnings |
| when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y: |
| |
| WARNING: suspicious RCU usage |
| kernel/events/core.c:8168 RCU-list traversed in non-reader section!! |
| |
| Call Trace: |
| lockdep_rcu_suspicious |
| ? perf_event_addr_filters_apply |
| perf_iterate_ctx |
| perf_event_exec |
| begin_new_exec |
| ? load_elf_phdrs |
| load_elf_binary |
| ? lock_acquire |
| ? find_held_lock |
| ? bprm_execve |
| bprm_execve |
| do_execveat_common.isra.0 |
| __x64_sys_execve |
| do_syscall_64 |
| entry_SYSCALL_64_after_hwframe |
| |
| This protection was previously present but was removed in commit |
| bd2756811766 ("perf: Rewrite core context handling"). Add back the |
| necessary rcu_read_lock()/rcu_read_unlock() pair around |
| perf_iterate_ctx() call in perf_event_exec(). |
| |
| [ mingo: Use scoped_guard() as suggested by Peter ] |
| |
| The Linux kernel CVE team has assigned CVE-2025-21889 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.2 with commit bd27568117664b8b3e259721393df420ed51f57b and fixed in 6.6.81 with commit f390c2eea571945f357a2d3b9fcb1c015767132e |
| Issue introduced in 6.2 with commit bd27568117664b8b3e259721393df420ed51f57b and fixed in 6.12.18 with commit a2475ccad6120546ea45dbcd6cd1f74dc565ef6b |
| Issue introduced in 6.2 with commit bd27568117664b8b3e259721393df420ed51f57b and fixed in 6.13.6 with commit dd536566dda9a551fc2a2acfab5313a5bb13ed02 |
| Issue introduced in 6.2 with commit bd27568117664b8b3e259721393df420ed51f57b and fixed in 6.14 with commit 0fe8813baf4b2e865d3b2c735ce1a15b86002c74 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21889 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| kernel/events/core.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/f390c2eea571945f357a2d3b9fcb1c015767132e |
| https://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b |
| https://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02 |
| https://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74 |
