{"id":"AZL-97746","summary":"CVE-2026-74740 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_api: fix TOCTOU NULL deref on a-\u003egoto_chain\n\ntcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking\nrcu_access_pointer(a-\u003egoto_chain) and then calling\ntcf_action_goto_chain_exec(), which does a second, independent\nrcu_dereference_bh(a-\u003egoto_chain) read and immediately dereferences\nchain-\u003efilter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact\nreplace path) can clear a-\u003egoto_chain between the two reads, so the second\nread returns NULL and tcf_action_goto_chain_exec() dereferences NULL.\n\nFix the race by doing a single rcu_dereference_bh() read of a-\u003egoto_chain\nin tcf_action_exec(), checking it once for NULL, and passing the resulting\nchain pointer into tcf_action_goto_chain_exec(). This turns the split\ncheck/use into a single check/use on one value.","modified":"2026-08-30T05:26:50Z","published":"2026-08-26T15:16:52Z","upstream":["CVE-2026-74740"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74740"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-97746.json"}}],"schema_version":"1.9.0"}