CVE-2024-26841
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
In the Linux kernel for LoongArch architecture, a bug was fixed where cpu_sibling_map was not updated when disabling non-boot CPUs. This caused errors on SMT systems such as 'jump label: negative count!' and kernel warnings. The fix defines and calls clear_cpu_sibling_map().
Risk Assessment
On LoongArch systems with SMT enabled, disabling CPUs can trigger kernel warnings and potentially lead to system instability. This may result in unpredictable behavior or crashes in power management or CPU hotplug scenarios.
Recommendation
Update the Linux kernel to a version containing this fix. If using LoongArch architecture, prioritize the update, especially on systems with SMT enabled.
Other vulnerabilities in Linux kernel
See all- CVE-2026-99259Unknown
In the Linux kernel, the soc/tegra: pmc driver has an uninitialised early_pmc->rate variable for legacy 32-bit Tegra devices. The variable is never configured and remains 0, triggering a warning in tegra_pmc_enter_suspend_mode(). The issue appeared after the PMC driver was changed to create the PMC context dynamically, updating rate only in the new context.
- CVE-2026-99258Unknown
In the Linux kernel, hv_apicid_to_vp_index() uses per-CPU hypercall input and output pages. In an SEV-SNP CoCo VM without a paravisor the output page is not allocated, so the hypervisor stores the resulting VP index into memory not allocated by the guest. The fix uses the input page for both input and output.
- CVE-2026-99257Unknown
In the Linux kernel, the shared GPIO mechanism based on platform lookup tables requires an associated struct device. An fwnode-based lookup with no associated device currently causes a NULL-pointer dereference. The fix adds a check that lets the kernel gracefully handle this situation with an error.
- CVE-2026-99256Unknown
In the Linux kernel, the dm cache module used a rw_semaphore for background_work_lock, although write locks on rw_semaphores have strict owner semantics. The locking process was not always the same as the unlocking one, triggering a warning with CONFIG_DEBUG_RWSEMS during suspend/resume of a cache device. The fix replaces the rw_semaphore with a spinlock and a wait queue.
- CVE-2026-99251Unknown
In the Linux kernel, init_vp_index() contains a retry loop that strips CPUs from a node if they are already in the allocated cpumask or outside the HK_TYPE_MANAGED_IRQ housekeeping cpumask. If the housekeeping cpumask contains no CPU in that node, the loop becomes infinite. The fix skips NUMA nodes with no housekeeping CPU and aborts early when no online housekeeping CPUs exist.
- CVE-2026-99250Unknown
In the Linux kernel, the NBCON console printing kthreads are started very early during boot via early_initcall(). Asynchronously enabling/disabling interrupts during early boot may interfere with early SMP setup on some hardware platforms, causing hangs. The fix postpones kthread startup until after all arch initcalls have completed.
- CVE-2026-99249Unknown
In the Linux kernel, zap_pid_ns_processes() waiting for PID namespace cleanup was not freezable. A tracer outside the namespace that does not reap its traced zombies keeps PIDs allocated, making the wait unbounded and causing every suspend attempt to fail. The fix makes the wait loops use TASK_FREEZABLE states so the freezer can freeze waiting tasks.
- CVE-2026-99248Unknown
In the Linux kernel, the i2c: xiic driver was changed to restore non-managed runtime PM instead of the devres-based approach to fix a clk WARN flood. The managed release tore down runtime PM in the wrong order, causing the clock to be disabled twice and triggering "clkN already disabled" warnings on every teardown.
- CVE-2026-99247Unknown
In the Linux kernel, if trace buffer allocation fails during early boot, tracing_disabled remains set and the global trace array events list stays uninitialized. tracer_init_tracefs_work_func() runs asynchronously without checking this state and calls event_trace_init() and init_tracer_tracefs(), leading to a NULL pointer dereference Oops during boot. The fix checks tracing_disabled at the start of the work function.
- CVE-2026-99215Unknown
In the Linux kernel power supply subsystem, a use-after-free vulnerability exists. If a power supply is unregistered while its external_power_changed() callback is still running, the driver may free data that the callback is still accessing, leading to a kernel crash (NULL pointer dereference).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: LoongArch: Update cpu_sibling_map when disabling nonboot CPUs Update cpu_sibling_map when disabling nonboot CPUs by defining & calling clear_cpu_sibling_map(), otherwise we get such errors on SMT systems: jump label: negative count! WARNING: CPU: 6 PID: 45 at kernel/jump_label.c:263 __static_key_slow_dec_cpuslocked+0xec/0x100 CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 pc 90000000004c302c ra 90000000004c302c tp 90000001005bc000 sp 90000001005bfd20 a0 000000000000001b a1 900000000224c278 a2 90000001005bfb58 a3 900000000224c280 a4 900000000224c278 a5 90000001005bfb50 a6 0000000000000001 a7 0000000000000001 t0 ce87a4763eb5234a t1 ce87a4763eb5234a t2 0000000000000000 t3 0000000000000000 t4 0000000000000006 t5 0000000000000000 t6 0000000000000064 t7 0000000000001964 t8 000000000009ebf6 u0 9000000001f2a068 s9 0000000000000000 s0 900000000246a2d8 s1 ffffffffffffffff s2 ffffffffffffffff s3 90000000021518c0 s4 0000000000000040 s5 9000000002151058 s6 9000000009828e40 s7 00000000000000b4 s8 0000000000000006 ra: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 ERA: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1c (LIE=2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014d000 (Loongson-64bit, Loongson-3A6000-HV) CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 Stack : 0000000000000000 900000000203f258 900000000179afc8 90000001005bc000 90000001005bf980 0000000000000000 90000001005bf988 9000000001fe0be0 900000000224c280 900000000224c278 90000001005bf8c0 0000000000000001 0000000000000001 ce87a4763eb5234a 0000000007f38000 90000001003f8cc0 0000000000000000 0000000000000006 0000000000000000 4c206e6f73676e6f 6f4c203a656d616e 000000000009ec99 0000000007f38000 0000000000000000 900000000214b000 9000000001fe0be0 0000000000000004 0000000000000000 0000000000000107 0000000000000009 ffffffffffafdabe 00000000000000b4 0000000000000006 90000000004c302c 9000000000224528 00005555939a0c7c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c ... Call Trace: [<9000000000224528>] show_stack+0x48/0x1a0 [<900000000179afc8>] dump_stack_lvl+0x78/0xa0 [<9000000000263ed0>] __warn+0x90/0x1a0 [<90000000017419b8>] report_bug+0x1b8/0x280 [<900000000179c564>] do_bp+0x264/0x420 [<90000000004c302c>] __static_key_slow_dec_cpuslocked+0xec/0x100 [<90000000002b4d7c>] sched_cpu_deactivate+0x2fc/0x300 [<9000000000266498>] cpuhp_invoke_callback+0x178/0x8a0 [<9000000000267f70>] cpuhp_thread_fun+0xf0/0x240 [<90000000002a117c>] smpboot_thread_fn+0x1dc/0x2e0 [<900000000029a720>] kthread+0x140/0x160 [<9000000000222288>] ret_from_kernel_thread+0xc/0xa4
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

