In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_sdei: Fix sleep from invalid context BUG
Running a preempt-rt (v6.2-rc3-rt1) based kernel on an Ampere Altra triggers:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by cpuhp/0/24: #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130 irq event stamp: 36 hardirqs last enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0 hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248 softirqs last enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...] Hardware name: WIWYNN Mt.Jade Server [...] Call trace: dump_backtrace+0x114/0x120 show_stack+0x20/0x70 dump_stack_lvl+0x9c/0xd8 dump_stack+0x18/0x34 __might_resched+0x188/0x228 rt_spin_lock+0x70/0x120 sdei_cpuhp_up+0x3c/0x130 cpuhp_invoke_callback+0x250/0xf08 cpuhp_thread_fun+0x120/0x248 smpboot_thread_fn+0x280/0x320 kthread+0x130/0x140 ret_from_fork+0x10/0x20
sdei_cpuhp_up() is called in the STARTING hotplug section, which runs with interrupts disabled. Use a CPUHP_AP_ONLINE_DYN entry instead to execute the cpuhp cb later, with preemption enabled.
SDEI originally got its own cpuhp slot to allow interacting with perf. It got superseded by pNMI and this early slot is not relevant anymore. [1]
Some SDEI calls (e.g. SDEI_1_0_FN_SDEI_PE_MASK) take actions on the calling CPU. It is checked that preemption is disabled for them. _ONLINE cpuhp cb are executed in the 'per CPU hotplug thread'. Preemption is enabled in those threads, but their cpumask is limited to 1 CPU. Move 'WARN_ON_ONCE(preemptible())' statements so that SDEI cpuhp cb don't trigger them.
Also add a check for the SDEI_1_0_FN_SDEI_PRIVATE_RESET SDEI call which acts on the calling CPU.
[1]: https://lore.kernel.org/all/[email protected]/
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-debuginfo-common-x86_64Upgrade kernel-toolsUpgrade kernel-livepatch-5.15.117-72.142Upgrade kernel-livepatch-5.10.184-174.730Upgrade bpftool-debuginfoUpgrade python-perfUpgrade perf-debuginfoUpgrade kernel-tools-debuginfoUpgrade perfUpgrade kernelUpgrade kernel-debuginfo-common-aarch64Upgrade bpftoolUpgrade kernel-tools-develUpgrade python-perf-debuginfoUpgrade kernel-develUpgrade kernel-headersUpgrade kernel-debuginfo | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade kernel-libbpfUpgrade perf-debuginfoUpgrade kernel-livepatch-6.1.34-56.100Upgrade kernelUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-debuginfoUpgrade kernel-headersUpgrade kernel-libbpf-develUpgrade bpftool-debuginfoUpgrade perfUpgrade kernel-libbpf-staticUpgrade kernel-develUpgrade kernel-tools-develUpgrade bpftoolUpgrade kernel-toolsUpgrade python3-perfUpgrade python3-perf-debuginfoUpgrade kernel-debuginfo-common-aarch64 | Feb 20, 2026 | Dec 24, 2025 |
| Debian | — | Upgrade linux | Dec 29, 2025 | Dec 29, 2025 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Dec 24, 2025 |
| Ubuntu | — | Upgrade linux-raspi-5.4Upgrade linux-gcp-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-aws-5.15Upgrade linux-hwe-5.4Upgrade linux-kvmUpgrade linux-intel-iotgUpgrade linux-xilinx-zynqmpUpgrade linux-aws-fipsUpgrade linux-azureUpgrade linux-raspiUpgrade linux-oracle-5.15Upgrade linux-oracleUpgrade linux-azure-5.4Upgrade linux-nvidiaUpgrade linux-aws-5.4Upgrade linux-gkeopUpgrade linux-gcp-fipsUpgrade linux-bluefieldUpgrade linux-fipsUpgrade linux-iotUpgrade linux-ibmUpgrade linux-azure-5.15Upgrade linux-lowlatencyUpgrade linux-realtimeUpgrade linux-intel-iotg-5.15Upgrade linux-hwe-5.15Upgrade linux-nvidia-tegra-igxUpgrade linux-azure-fde-5.15Upgrade linux-oracle-5.4Upgrade linux-riscv-5.15Upgrade linux-ibm-5.4Upgrade linux-gcp-5.4Upgrade linux-azure-fipsUpgrade linux-gkeUpgrade linux-nvidia-tegra-5.15Upgrade linux-nvidia-tegraUpgrade linux-intel-iot-realtimeUpgrade linux-ibm-5.15Upgrade linuxUpgrade linux-awsUpgrade linux-gcp | Jan 6, 2026 | Dec 24, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Dec 24, 2025 |
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