{"id":"AZL-96018","summary":"CVE-2026-74338 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject sleepable BPF_LSM_CGROUP programs at load time\n\nThe cgroup shim runs under rcu_read_lock_dont_migrate(), so we should\nnot attach any sleepable BPF programs there. Add support to the verifier\nto explicitly reject attempts to load sleepable BPF programs destined\nfor LSM cgroup attachment.\n\nWithout this, we get the following splat from a BPF_LSM_CGROUP\nprogram marked BPF_F_SLEEPABLE attached to file_open when it calls\nbpf_get_dentry_xattr():\n\n  BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567\n  in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load\n  preempt_count: 0, expected: 0\n  RCU nest depth: 2, expected: 0\n  Call Trace:\n   down_read+0x76/0x480\n   ext4_xattr_get+0x11f/0x700\n   __vfs_getxattr+0xf0/0x150\n   bpf_get_dentry_xattr+0xbb/0xf0\n   bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85\n   __cgroup_bpf_run_lsm_current+0x326/0x840\n   bpf_trampoline_6442534646+0x62/0x14d\n   security_file_open+0x34/0x60\n   do_dentry_open+0x340/0x1260\n   vfs_open+0x7a/0x440\n   path_openat+0x1bac/0x30a0\n\nlibbpf provides a .s named section variant for every sleepable\nprogram type except lsm_cgroup, reflecting that per-cgroup LSM programs\nare intended to only run in a non-sleepable context.\n\nThe above splat was obtained by bypassing libbpf by using bpf(2)\ndirectly.","modified":"2026-08-31T05:26:27Z","published":"2026-08-15T06:22:34Z","upstream":["CVE-2026-74338"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74338"}],"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-96018.json"}}],"schema_version":"1.9.0"}