Linux aws: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop… (CVE-2026-31498)
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.
Linux aws: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop… (CVE-2026-31498)
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.
CVSS v3.1
Score 5.5medium
Affected software
pkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]~14.04.1?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]~14.04.1?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.2?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.2?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.2?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]+cvm1.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.3?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email 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protected]+fips1?arch=source&distro=fips-updates/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.2?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]~22.04.1?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email 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protected]?arch=source&distro=bluefield/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-preview/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-preview/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-preview/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-preview/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/jammypkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/jammypkg:deb/ubuntu/[email protected]?arch=source&distro=realtime/jammypkg:deb/ubuntu/[email protected]?arch=source&distro=realtime/jammypkg:deb/ubuntu/[email protected]~22.04.2?arch=source&distro=realtime/jammypkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email 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protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=bluefield/noblepkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/noblepkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/noblepkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/noblepkg:deb/ubuntu/[email protected]+fips1?arch=source&distro=fips-updates/noblepkg:deb/ubuntu/[email protected]?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]~24.04.1?arch=source&distro=realtime/noblepkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-31498
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:16.04:LTS","Ubuntu:Pro:FIPS:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:18.04:LTS","Ubuntu:Pro:FIPS-updates:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:20.04:LTS","Ubuntu:Pro:FIPS-updates:20.04:LTS","Ubuntu:Pro:FIPS:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:Nvidia-BlueField:22.04:LTS","Ubuntu:Pro:FIPS-preview:22.04:LTS","Ubuntu:Pro:FIPS-updates:22.04:LTS","Ubuntu:Pro:Realtime:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:Nvidia-BlueField:24.04:LTS","Ubuntu:Pro:FIPS-updates:24.04:LTS","Ubuntu:Pro:Realtime:24.04:LTS","Ubuntu:25.10"]
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5b62352d1edb114c88b091
Added to database: 07/18/2026, 11:23:33 UTC
Last updated: 07/31/2026, 19:30:32 UTC
Views: 3
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