CVE-2026-64537

Name	CVE-2026-64537
Description	In the Linux kernel, the following vulnerability has been resolved: bridge: cfm: reject invalid CCM interval at configuration time ccm_tx_work_expired() re-arms itself via queue_delayed_work() using the configured exp_interval converted by interval_to_us(). When exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range, interval_to_us() returns 0, causing the worker to fire immediately in a tight loop that allocates skbs until OOM. Fix this by validating exp_interval at configuration time: - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the netlink policy so userspace cannot set an invalid value. - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has not yet been configured (defaults to 0 from kzalloc).
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-6405-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.259-1	fixed
	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.177-1	vulnerable
	trixie	6.12.94-1	vulnerable
	trixie (security)	6.12.100-1	fixed
	forky	7.1.3-1	vulnerable
	sid	7.1.5-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	(not affected)
linux	source	trixie	6.12.100-1	DSA-6405-1
linux	source	(unstable)	7.1.5-1

[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/f3e02edd8322b31b8e6517faa6ba053bf29d1e26 (7.2-rc1)