| 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-2024-57934: fgraph: Add READ_ONCE() when accessing fgraph_array[] |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| fgraph: Add READ_ONCE() when accessing fgraph_array[] |
| |
| In __ftrace_return_to_handler(), a loop iterates over the fgraph_array[] |
| elements, which are fgraph_ops. The loop checks if an element is a |
| fgraph_stub to prevent using a fgraph_stub afterward. |
| |
| However, if the compiler reloads fgraph_array[] after this check, it might |
| race with an update to fgraph_array[] that introduces a fgraph_stub. This |
| could result in the stub being processed, but the stub contains a null |
| "func_hash" field, leading to a NULL pointer dereference. |
| |
| To ensure that the gops compared against the fgraph_stub matches the gops |
| processed later, add a READ_ONCE(). A similar patch appears in commit |
| 63a8dfb ("function_graph: Add READ_ONCE() when accessing fgraph_array[]"). |
| |
| The Linux kernel CVE team has assigned CVE-2024-57934 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit 37238abe3cb47b8daaa8706c9949f67b2a705cf1 and fixed in 6.12.9 with commit b68b2a3fbacc7be720ef589d489bcacdd05c6d38 |
| Issue introduced in 6.11 with commit 37238abe3cb47b8daaa8706c9949f67b2a705cf1 and fixed in 6.13 with commit d65474033740ded0a4fe9a097fce72328655b41d |
| |
| 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-2024-57934 |
| 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/trace/fgraph.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/b68b2a3fbacc7be720ef589d489bcacdd05c6d38 |
| https://git.kernel.org/stable/c/d65474033740ded0a4fe9a097fce72328655b41d |
