Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop (Linux Linux)

CVE-2026-31498
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.12 % · centile 2 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED state to support L2CAP reconfiguration (e.g. MTU changes). However, since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from the initial configuration, the reconfiguration path falls through to l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and retrans_list without freeing the previous allocations and sets chan->sdu to NULL without freeing the existing skb. This leaks all previously allocated ERTM resources. Additionally, l2cap_parse_conf_req() does not validate the minimum value of remote_mps derived from the RFC max_pdu_size option. A zero value propagates to l2cap_segment_sdu() where pdu_len becomes zero, causing the while loop to never terminate since len is never decremented, exhausting all available memory. Fix the double-init by skipping l2cap_ertm_init() and l2cap_chan_ready() when the channel is already in BT_CONNECTED state, while still allowing the reconfiguration parameters to be updated through l2cap_parse_conf_req(). Also add a pdu_len zero check in l2cap_segment_sdu() as a safeguard.

Faiblesses (CWE)

  • CWE-835 — Boucle dont la condition de sortie est inatteignable (boucle infinie)

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 96298f640104e4cd9a913a6e50b0b981829b94ff < 9760b83cfd24b38caee663f429011a0dd6064fa9 ; affected 96298f640104e4cd9a913a6e50b0b981829b94ff < de37e2655b7abc3f59254c6b72256840f39fc6d5 ; affected 96298f640104e4cd9a913a6e50b0b981829b94ff < e7aab23b7df89a3d754a5f0a7d2237548b328bd0 ; affected 96298f640104e4cd9a913a6e50b0b981829b94ff < 52667c859fe33f70c2e711cb81bbd505d5eb8e75 ; affected 96298f640104e4cd9a913a6e50b0b981829b94ff < 9a21a631ee034b1573dce14b572a24943dbfd7ae ; affected 96298f640104e4cd9a913a6e50b0b981829b94ff < 900e4db5385ec2cacd372345a80ab9c8e105b3a3
Linux · Linuxaffected 5.7 ; unaffected 0 < 5.7 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.131 ≤ 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