| 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-2024-50130: netfilter: bpf: must hold reference on net namespace |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: bpf: must hold reference on net namespace |
| |
| BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0 |
| Read of size 8 at addr ffff8880106fe400 by task repro/72= |
| bpf_nf_link_release+0xda/0x1e0 |
| bpf_link_free+0x139/0x2d0 |
| bpf_link_release+0x68/0x80 |
| __fput+0x414/0xb60 |
| |
| Eric says: |
| It seems that bpf was able to defer the __nf_unregister_net_hook() |
| after exit()/close() time. |
| Perhaps a netns reference is missing, because the netns has been |
| dismantled/freed already. |
| bpf_nf_link_attach() does : |
| link->net = net; |
| But I do not see a reference being taken on net. |
| |
| Add such a reference and release it after hook unreg. |
| Note that I was unable to get syzbot reproducer to work, so I |
| do not know if this resolves this splat. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50130 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit 84601d6ee68ae820dec97450934797046d62db4b and fixed in 6.6.59 with commit f41bd93b3e0508edc7ba820357f949071dcc0acc |
| Issue introduced in 6.4 with commit 84601d6ee68ae820dec97450934797046d62db4b and fixed in 6.11.6 with commit d0d7939543a1b3bb93af9a18d258a774daf8f162 |
| Issue introduced in 6.4 with commit 84601d6ee68ae820dec97450934797046d62db4b and fixed in 6.12 with commit 1230fe7ad3974f7bf6c78901473e039b34d4fb1f |
| |
| 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-2024-50130 |
| 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: |
| net/netfilter/nf_bpf_link.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/f41bd93b3e0508edc7ba820357f949071dcc0acc |
| https://git.kernel.org/stable/c/d0d7939543a1b3bb93af9a18d258a774daf8f162 |
| https://git.kernel.org/stable/c/1230fe7ad3974f7bf6c78901473e039b34d4fb1f |
