| 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-2023-52924: netfilter: nf_tables: don't skip expired elements during walk |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: nf_tables: don't skip expired elements during walk |
| |
| There is an asymmetry between commit/abort and preparation phase if the |
| following conditions are met: |
| |
| 1. set is a verdict map ("1.2.3.4 : jump foo") |
| 2. timeouts are enabled |
| |
| In this case, following sequence is problematic: |
| |
| 1. element E in set S refers to chain C |
| 2. userspace requests removal of set S |
| 3. kernel does a set walk to decrement chain->use count for all elements |
| from preparation phase |
| 4. kernel does another set walk to remove elements from the commit phase |
| (or another walk to do a chain->use increment for all elements from |
| abort phase) |
| |
| If E has already expired in 1), it will be ignored during list walk, so its use count |
| won't have been changed. |
| |
| Then, when set is culled, ->destroy callback will zap the element via |
| nf_tables_set_elem_destroy(), but this function is only safe for |
| elements that have been deactivated earlier from the preparation phase: |
| lack of earlier deactivate removes the element but leaks the chain use |
| count, which results in a WARN splat when the chain gets removed later, |
| plus a leak of the nft_chain structure. |
| |
| Update pipapo_get() not to skip expired elements, otherwise flush |
| command reports bogus ENOENT errors. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52924 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 4.19.316 with commit 94313a196b44184b5b52c1876da6a537701b425a |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 5.4.262 with commit 1da4874d05da1526b11b82fc7f3c7ac38749ddf8 |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 5.10.198 with commit b15ea4017af82011dd55225ce77cce3d4dfc169c |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 5.15.134 with commit 7c7e658a36f8b1522bd3586d8137e5f93a25ddc5 |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 6.1.56 with commit 59dab3bf0b8fc08eb802721c0532f13dd89209b8 |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 6.4.11 with commit bd156ce9553dcaf2d6ee2c825d1a5a1718e86524 |
| Issue introduced in 4.1 with commit 9d0982927e79049675cb6c6c04a0ebb3dad5a434 and fixed in 6.5 with commit 24138933b97b055d486e8064b4a1721702442a9b |
| |
| 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-2023-52924 |
| 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 |
| net/netfilter/nft_set_hash.c |
| net/netfilter/nft_set_pipapo.c |
| net/netfilter/nft_set_rbtree.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/94313a196b44184b5b52c1876da6a537701b425a |
| https://git.kernel.org/stable/c/1da4874d05da1526b11b82fc7f3c7ac38749ddf8 |
| https://git.kernel.org/stable/c/b15ea4017af82011dd55225ce77cce3d4dfc169c |
| https://git.kernel.org/stable/c/7c7e658a36f8b1522bd3586d8137e5f93a25ddc5 |
| https://git.kernel.org/stable/c/59dab3bf0b8fc08eb802721c0532f13dd89209b8 |
| https://git.kernel.org/stable/c/bd156ce9553dcaf2d6ee2c825d1a5a1718e86524 |
| https://git.kernel.org/stable/c/24138933b97b055d486e8064b4a1721702442a9b |
