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netfilter: nft_set_pipapo: do not free live element (Linux Linux)

CVE-2024-26924
HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.85 % · percentile 58 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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Description

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)

Weaknesses (CWE)

  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1MEDIUM 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HCISA-ADP
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
CVSS 3.1MEDIUM 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 3c4287f62044a90e73a561aa05fc46e62da173da < e3b887a9c11caf8357a821260e095f2a694a34f2 ; affected 3c4287f62044a90e73a561aa05fc46e62da173da < 7a1679e2d9bfa3b5f8755c2c7113e54b7d42bd46 ; affected 3c4287f62044a90e73a561aa05fc46e62da173da < 41d8fdf3afaff312e17466e4ab732937738d5644 ; affected 3c4287f62044a90e73a561aa05fc46e62da173da < ebf7c9746f073035ee26209e38c3a1170f7b349a ; affected 3c4287f62044a90e73a561aa05fc46e62da173da < 14b001ba221136c15f894577253e8db535b99487 ; affected 3c4287f62044a90e73a561aa05fc46e62da173da < 3cfc9ec039af60dbd8965ae085b2c2ccdcfbe1cc
Linux · Linuxaffected 5.6 ; unaffected 0 < 5.6 ; unaffected 5.10.216 ≤ 5.10.* ; unaffected 5.15.157 ≤ 5.15.* ; unaffected 6.1.88 ≤ 6.1.* ; unaffected 6.6.29 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD