| 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-2024-40909: bpf: Fix a potential use-after-free in bpf_link_free() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bpf: Fix a potential use-after-free in bpf_link_free() |
| |
| After commit 1a80dbcb2dba, bpf_link can be freed by |
| link->ops->dealloc_deferred, but the code still tests and uses |
| link->ops->dealloc afterward, which leads to a use-after-free as |
| reported by syzbot. Actually, one of them should be sufficient, so |
| just call one of them instead of both. Also add a WARN_ON() in case |
| of any problematic implementation. |
| |
| The Linux kernel CVE team has assigned CVE-2024-40909 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6.26 with commit 876941f533e7b47fc69977fc4551c02f2d18af97 and fixed in 6.6.35 with commit 91cff53136daeff50816b0baeafd38a6976f6209 |
| Issue introduced in 6.9 with commit 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce and fixed in 6.9.6 with commit fa97b8fed9896f1e89cb657513e483a152d4c382 |
| Issue introduced in 6.9 with commit 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce and fixed in 6.10 with commit 2884dc7d08d98a89d8d65121524bb7533183a63a |
| Issue introduced in 6.8.5 with commit 5d8d447777564b35f67000e7838e7ccb64d525c8 |
| |
| 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-2024-40909 |
| 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/bpf/syscall.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/91cff53136daeff50816b0baeafd38a6976f6209 |
| https://git.kernel.org/stable/c/fa97b8fed9896f1e89cb657513e483a152d4c382 |
| https://git.kernel.org/stable/c/2884dc7d08d98a89d8d65121524bb7533183a63a |
