Linux Kernel eBPF Vulnerability Rated 7.8 CVSS

Status: UPDATED  |  Advisory ID: CVE-2026-74338

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject sleepable BPF_LSM_CGROUP programs at load time

The cgroup shim runs under rcu_read_lock_dont_migrate(), so we should

not attach any sleepable BPF programs there. Add support to the verifier

to explicitly reject attempts to load sleepable BPF programs destined

for LSM cgroup attachment.

Without this, we get the following splat from a BPF_LSM_CGROUP

program marked BPF_F_SLEEPABLE attached to file_open when it calls

bpf_get_dentry_xattr():

BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567

in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load

preempt_count: 0, expected: 0

RCU nest depth: 2, expected: 0

Call Trace:

down_read+0x76/0x480

ext4_xattr_get+0x11f/0x700

__vfs_getxattr+0xf0/0x150

bpf_get_dentry_xattr+0xbb/0xf0

bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85

__cgroup_bpf_run_lsm_current+0x326/0x840

bpf_trampoline_6442534646+0x62/0x14d

security_file_open+0x34/0x60

do_dentry_open+0x340/0x1260

vfs_open+0x7a/0x440

path_openat+0x1bac/0x30a0

libbpf provides a .s named section variant for every sleepable

program type except lsm_cgroup, reflecting that per-cgroup LSM programs

are intended to only run in a non-sleepable context.

The above splat was obtained by bypassing libbpf by using bpf(2)

directly. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References