CVE-2024-50138

/// Technical description

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

bpf: Use raw_spinlock_t in ringbuf

The function __bpf_ringbuf_reserve is invoked from a tracepoint, which

disables preemption. Using spinlock_t in this context can lead to a

"sleep in atomic" warning in the RT variant. This issue is illustrated

in the example below:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48

in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 556208, name: test_progs

preempt_count: 1, expected: 0

RCU nest depth: 1, expected: 1

INFO: lockdep is turned off.

Preemption disabled at:

[<ffffd33a5c88ea44>] migrate_enable+0xc0/0x39c

CPU: 7 PID: 556208 Comm: test_progs Tainted: G

Hardware name: Qualcomm SA8775P Ride (DT)

Call trace:

dump_backtrace+0xac/0x130

show_stack+0x1c/0x30

dump_stack_lvl+0xac/0xe8

dump_stack+0x18/0x30

__might_resched+0x3bc/0x4fc

rt_spin_lock+0x8c/0x1a4

__bpf_ringbuf_reserve+0xc4/0x254

bpf_ringbuf_reserve_dynptr+0x5c/0xdc

bpf_prog_a

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References