| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49873: bpf: Fix wrong reg type conversion in release_reference() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bpf: Fix wrong reg type conversion in release_reference() |
| |
| Some helper functions will allocate memory. To avoid memory leaks, the |
| verifier requires the eBPF program to release these memories by calling |
| the corresponding helper functions. |
| |
| When a resource is released, all pointer registers corresponding to the |
| resource should be invalidated. The verifier use release_references() to |
| do this job, by apply __mark_reg_unknown() to each relevant register. |
| |
| It will give these registers the type of SCALAR_VALUE. A register that |
| will contain a pointer value at runtime, but of type SCALAR_VALUE, which |
| may allow the unprivileged user to get a kernel pointer by storing this |
| register into a map. |
| |
| Using __mark_reg_not_init() while NOT allow_ptr_leaks can mitigate this |
| problem. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49873 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.20 with commit fd978bf7fd312581a7ca454a991f0ffb34c4204b and fixed in 5.10.155 with commit cedd4f01f67be94735f15123158f485028571037 |
| Issue introduced in 4.20 with commit fd978bf7fd312581a7ca454a991f0ffb34c4204b and fixed in 5.15.79 with commit 466ce46f251dfb259a8cbaa895ab9edd6fb56240 |
| Issue introduced in 4.20 with commit fd978bf7fd312581a7ca454a991f0ffb34c4204b and fixed in 6.0.9 with commit ae5ccad6c711db0f2ca1231be051935dd128b8f5 |
| Issue introduced in 4.20 with commit fd978bf7fd312581a7ca454a991f0ffb34c4204b and fixed in 6.1 with commit f1db20814af532f85e091231223e5e4818e8464b |
| |
| 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-2022-49873 |
| 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/verifier.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/cedd4f01f67be94735f15123158f485028571037 |
| https://git.kernel.org/stable/c/466ce46f251dfb259a8cbaa895ab9edd6fb56240 |
| https://git.kernel.org/stable/c/ae5ccad6c711db0f2ca1231be051935dd128b8f5 |
| https://git.kernel.org/stable/c/f1db20814af532f85e091231223e5e4818e8464b |
