| 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-2024-44968: tick/broadcast: Move per CPU pointer access into the atomic section |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tick/broadcast: Move per CPU pointer access into the atomic section |
| |
| The recent fix for making the take over of the broadcast timer more |
| reliable retrieves a per CPU pointer in preemptible context. |
| |
| This went unnoticed as compilers hoist the access into the non-preemptible |
| region where the pointer is actually used. But of course it's valid that |
| the compiler keeps it at the place where the code puts it which rightfully |
| triggers: |
| |
| BUG: using smp_processor_id() in preemptible [00000000] code: |
| caller is hotplug_cpu__broadcast_tick_pull+0x1c/0xc0 |
| |
| Move it to the actual usage site which is in a non-preemptible region. |
| |
| The Linux kernel CVE team has assigned CVE-2024-44968 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.1.103 with commit 408bfb6b0a7f22e971ce6b600aec448769e580a8 and fixed in 6.1.105 with commit 7b3ec186ba93e333e9efe7254e7e31c1828e5d2d |
| Issue introduced in 6.6.44 with commit 3a58c590f6bd1d20eb1e76c5cea31c36cc032339 and fixed in 6.6.46 with commit b9d604933d5fd72dd37f24e1dc35f778297d745a |
| Issue introduced in 6.10.3 with commit 2cdab4b4bf77369961f706cdeb7d040db10c5217 and fixed in 6.10.5 with commit 7dd12f85f150010ef7518201c63fa7e395f5c3e9 |
| |
| 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-2024-44968 |
| 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/time/tick-broadcast.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/f54abf332a2bc0413cfa8bd6a8511f7aa99faea0 |
| https://git.kernel.org/stable/c/f91fb47ecacc178a83a77eeebd25cbaec18c01d6 |
| https://git.kernel.org/stable/c/668c6c4a7e9e9f081c06b70f30104fb7013437ed |
| https://git.kernel.org/stable/c/541a900d245536d4809cb1aa322c3fcc2cdb58a6 |
| https://git.kernel.org/stable/c/7b3ec186ba93e333e9efe7254e7e31c1828e5d2d |
| https://git.kernel.org/stable/c/b9d604933d5fd72dd37f24e1dc35f778297d745a |
| https://git.kernel.org/stable/c/7dd12f85f150010ef7518201c63fa7e395f5c3e9 |
| https://git.kernel.org/stable/c/6881e75237a84093d0986f56223db3724619f26e |
