| From bippy-1.2.0 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-2024-49987: bpftool: Fix undefined behavior in qsort(NULL, 0, ...) |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bpftool: Fix undefined behavior in qsort(NULL, 0, ...) |
| |
| When netfilter has no entry to display, qsort is called with |
| qsort(NULL, 0, ...). This results in undefined behavior, as UBSan |
| reports: |
| |
| net.c:827:2: runtime error: null pointer passed as argument 1, which is declared to never be null |
| |
| Although the C standard does not explicitly state whether calling qsort |
| with a NULL pointer when the size is 0 constitutes undefined behavior, |
| Section 7.1.4 of the C standard (Use of library functions) mentions: |
| |
| "Each of the following statements applies unless explicitly stated |
| otherwise in the detailed descriptions that follow: If an argument to a |
| function has an invalid value (such as a value outside the domain of |
| the function, or a pointer outside the address space of the program, or |
| a null pointer, or a pointer to non-modifiable storage when the |
| corresponding parameter is not const-qualified) or a type (after |
| promotion) not expected by a function with variable number of |
| arguments, the behavior is undefined." |
| |
| To avoid this, add an early return when nf_link_info is NULL to prevent |
| calling qsort with a NULL pointer. |
| |
| The Linux kernel CVE team has assigned CVE-2024-49987 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit d0fe92fb5e3df6991c640fb9205d880b68603259 and fixed in 6.6.55 with commit c2d9f9a7837ab29ccae0c42252f17d436bf0a501 |
| Issue introduced in 6.4 with commit d0fe92fb5e3df6991c640fb9205d880b68603259 and fixed in 6.10.14 with commit 2e0f6f33f2aa87493b365a38a8fd87b8854b7734 |
| Issue introduced in 6.4 with commit d0fe92fb5e3df6991c640fb9205d880b68603259 and fixed in 6.11.3 with commit c208b02827eb642758cef65641995fd3f38c89af |
| Issue introduced in 6.4 with commit d0fe92fb5e3df6991c640fb9205d880b68603259 and fixed in 6.12 with commit f04e2ad394e2755d0bb2d858ecb5598718bf00d5 |
| |
| 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-2024-49987 |
| 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: |
| tools/bpf/bpftool/net.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/c2d9f9a7837ab29ccae0c42252f17d436bf0a501 |
| https://git.kernel.org/stable/c/2e0f6f33f2aa87493b365a38a8fd87b8854b7734 |
| https://git.kernel.org/stable/c/c208b02827eb642758cef65641995fd3f38c89af |
| https://git.kernel.org/stable/c/f04e2ad394e2755d0bb2d858ecb5598718bf00d5 |
