UBUNTU-CVE-2026-80761: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: zero the sockaddr before returning it in getname isosockgetname() fills a struct sockaddriso in place and returns its size without clearing it first, so bytes it does not write are copied to user space from the kernel stack. The getsockname(2) and getpeername(2) paths both run through dogetsockname(), which hands getname() an uninitialized sockaddrstorage on the stack and copies back up to the number of bytes getname() returns, so the driver has to initialize every byte it accounts for. Two ranges are left uninitialized: - struct sockaddriso is 10 bytes but only 9 are written (family, isobdaddr, isobdaddrtype), leaking the trailing pad byte on every call. - for a broadcast peer (BISLINK or PALINK) the returned length grows by sizeof(struct sockaddrisobc), but only bcsid, bcnumbis and bcbis are filled; bcbdaddr and bcbdaddrtype, the first 7 bytes of that structure, are never written. An unprivileged process can open a BTPROTOISO socket and reach the pad leak with getsockname(); the broadcast leak needs an established BIS/PA connection. l2cap and rfcomm already memset their sockaddr in getname for the same reason; do the same here.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
Who can trigger the information leak?
An unprivileged local process can open a BTPROTO_ISO socket and use getsockname(2) to trigger the one-byte padding leak. The larger broadcast-related leak requires an established BIS or PA Bluetooth ISO connection.
What information can be exposed?
The basic path can expose one uninitialized trailing padding byte from struct sockaddr_iso. For broadcast peers, the returned address includes seven uninitialized bytes in sockaddr_iso_bc: bc_bdaddr and bc_bdaddr_type.
Which socket calls are affected?
Both getsockname(2) and getpeername(2) use the affected ISO socket getname path. The documented unprivileged trigger specifically uses getsockname(2), while the broadcast case depends on the connection state.
Which Ubuntu kernel packages are listed as affected?
The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, ubuntu/linux-hwe-edge, and ubuntu/linux-gkeop.