In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo: do not free live element Pablo reports a crash with large batches of elements with a back-to-back add/remove pattern. Quoting Pablo: add_elem("00000000") timeout 100 ms ... add_elem("0000000X") timeout 100 ms del_elem("0000000X") <---------------- delete one that was just added ... add_elem("00005000") timeout 100 ms 1) nft_pipapo_remove() removes element 0000000X Then, KASAN shows a splat. Looking at the remove function there is a chance that we will drop a rule that maps to a non-deactivated element. Removal happens in two steps, first we do a lookup for key k and return the to-be-removed element and mark it as inactive in the next generation. Then, in a second step, the element gets removed from the set/map. The _remove function does not work correctly if we have more than one element that share the same key. This can happen if we insert an element into a set when the set already holds an element with same key, but the element mapping to the existing key has timed out or is not active in the next generation. In such case its possible that removal will unmap the wrong element. If this happens, we will leak the non-deactivated element, it becomes unreachable. The element that got deactivated (and will be freed later) will remain reachable in the set data structure, this can result in a crash when such an element is retrieved during lookup (stale pointer). Add a check that the fully matching key does in fact map to the element that we have marked as inactive in the deactivation step. If not, we need to continue searching. Add a bug/warn trap at the end of the function as well, the remove function must not ever be called with an invisible/unreachable/non-existent element. v2: avoid uneeded temporary variable (Stefano)
History

Fri, 22 Nov 2024 12:00:00 +0000

Type Values Removed Values Added
References

Wed, 13 Nov 2024 02:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9

Wed, 06 Nov 2024 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:8::nfv
cpe:/o:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux

Tue, 05 Nov 2024 10:45:00 +0000

Type Values Removed Values Added
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-04-24T21:49:22.631Z

Updated: 2024-11-05T09:18:16.750Z

Reserved: 2024-02-19T14:20:24.194Z

Link: CVE-2024-26924

cve-icon Vulnrichment

Updated: 2024-08-02T00:21:05.445Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-04-25T06:15:57.407

Modified: 2024-11-21T09:03:23.677

Link: CVE-2024-26924

cve-icon Redhat

Severity : Low

Publid Date: 2024-04-24T00:00:00Z

Links: CVE-2024-26924 - Bugzilla