CVE-2026-43010

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

bpf: Reject sleepable kprobe_multi programs at attach time

kprobe.multi programs run in atomic/RCU context and cannot sleep. However, bpfkprobemultilinkattach() did not validate whether the program being attached had the sleepable flag set, allowing sleepable helpers such as bpfcopyfrom_user() to be invoked from a non-sleepable context.

This causes a "sleeping function called from invalid context" splat:

BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:169 inatomic(): 1, irqsdisabled(): 0, nonblock: 0, pid: 1787, name: sudo preemptcount: 1, expected: 0 RCU nest depth: 2, expected: 0

Fix this by rejecting sleepable programs early in bpfkprobemultilinkattach(), before any further processing.