Linux Kernel up to 6.1.114/6.11.5 bpf spinlock_rt.c in_atomic stack-based overflow

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.1.114/6.11.5. This vulnerability affects the function in_atomic of the file kernel/locking/spinlock_rt.c of the component bpf. Such manipulation leads to stack-based overflow. This vulnerability is referenced as CVE-2024-50138. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.114/6.11.5. It has been rated as critical. Affected by this issue is the function in_atomic of the file kernel/locking/spinlock_rt.c of the component bpf. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. CVE summarizes:

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: [] 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_ac3d15160d62622a_test_read_write+0x104/0x238 trace_call_bpf+0x238/0x774 perf_call_bpf_enter.isra.0+0x104/0x194 perf_syscall_enter+0x2f8/0x510 trace_sys_enter+0x39c/0x564 syscall_trace_enter+0x220/0x3c0 do_el0_svc+0x138/0x1dc el0_svc+0x54/0x130 el0t_64_sync_handler+0x134/0x150 el0t_64_sync+0x17c/0x180 Switch the spinlock to raw_spinlock_t to avoid this error.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-50138 since 10/21/2024. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/22/2025).

The vulnerability scanner Nessus provides a plugin with the ID 213018 (SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2024:4314-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.115 or 6.11.6 eliminates this vulnerability. Applying the patch 5eb34999d118/ca30e682e5d6/8b62645b09f8 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (213018) and CERT Bund (WID-SEC-2024-3339). Once again VulDB remains the best source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source eCryptfs
• SUSE openSUSE
• RESF Rocky Linux
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.114
• 6.11.0
• 6.11.1
• 6.11.2
• 6.11.3
• 6.11.4
• 6.11.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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