| 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-2021-47312: netfilter: nf_tables: Fix dereference of null pointer flow |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: nf_tables: Fix dereference of null pointer flow |
| |
| In the case where chain->flags & NFT_CHAIN_HW_OFFLOAD is false then |
| nft_flow_rule_create is not called and flow is NULL. The subsequent |
| error handling execution via label err_destroy_flow_rule will lead |
| to a null pointer dereference on flow when calling nft_flow_rule_destroy. |
| Since the error path to err_destroy_flow_rule has to cater for null |
| and non-null flows, only call nft_flow_rule_destroy if flow is non-null |
| to fix this issue. |
| |
| Addresses-Coverity: ("Explicity null dereference") |
| |
| The Linux kernel CVE team has assigned CVE-2021-47312 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13.2 with commit 09b1f676e2e0bbff67c568672c565c6f31470157 and fixed in 5.13.5 with commit 70a5a1950cca02c5cd161bb3846b4d983eed97d3 |
| |
| 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-2021-47312 |
| 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_tables_api.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/70a5a1950cca02c5cd161bb3846b4d983eed97d3 |
| https://git.kernel.org/stable/c/4ca041f919f13783b0b03894783deee00dbca19a |
