| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-50138: bpf: Use raw_spinlock_t in ringbuf |
| |
| 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_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 Linux kernel CVE team has assigned CVE-2024-50138 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.8 with commit 457f44363a8894135c85b7a9afd2bd8196db24ab and fixed in 6.1.115 with commit 5eb34999d118e69a20dc0c6556f315fcb0a1f8d3 |
| Issue introduced in 5.8 with commit 457f44363a8894135c85b7a9afd2bd8196db24ab and fixed in 6.6.84 with commit f9543375d9b150b2bcf16bb182e6b62309db0888 |
| Issue introduced in 5.8 with commit 457f44363a8894135c85b7a9afd2bd8196db24ab and fixed in 6.11.6 with commit ca30e682e5d6de44d12c4610767811c9a21d59ba |
| Issue introduced in 5.8 with commit 457f44363a8894135c85b7a9afd2bd8196db24ab and fixed in 6.12 with commit 8b62645b09f870d70c7910e7550289d444239a46 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-50138 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| kernel/bpf/ringbuf.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/5eb34999d118e69a20dc0c6556f315fcb0a1f8d3 |
| https://git.kernel.org/stable/c/f9543375d9b150b2bcf16bb182e6b62309db0888 |
| https://git.kernel.org/stable/c/ca30e682e5d6de44d12c4610767811c9a21d59ba |
| https://git.kernel.org/stable/c/8b62645b09f870d70c7910e7550289d444239a46 |
