{"id":"CVE-2024-49926","summary":"rcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb()\n\nFor kernels built with CONFIG_FORCE_NR_CPUS=y, the nr_cpu_ids is\ndefined as NR_CPUS instead of the number of possible cpus, this\nwill cause the following system panic:\n\nsmpboot: Allowing 4 CPUs, 0 hotplug CPUs\n...\nsetup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:512 nr_node_ids:1\n...\nBUG: unable to handle page fault for address: ffffffff9911c8c8\nOops: 0000 [#1] PREEMPT SMP PTI\nCPU: 0 PID: 15 Comm: rcu_tasks_trace Tainted: G W\n6.6.21 #1 5dc7acf91a5e8e9ac9dcfc35bee0245691283ea6\nRIP: 0010:rcu_tasks_need_gpcb+0x25d/0x2c0\nRSP: 0018:ffffa371c00a3e60 EFLAGS: 00010082\nCR2: ffffffff9911c8c8 CR3: 000000040fa20005 CR4: 00000000001706f0\nCall Trace:\n\u003cTASK\u003e\n? __die+0x23/0x80\n? page_fault_oops+0xa4/0x180\n? exc_page_fault+0x152/0x180\n? asm_exc_page_fault+0x26/0x40\n? rcu_tasks_need_gpcb+0x25d/0x2c0\n? __pfx_rcu_tasks_kthread+0x40/0x40\nrcu_tasks_one_gp+0x69/0x180\nrcu_tasks_kthread+0x94/0xc0\nkthread+0xe8/0x140\n? __pfx_kthread+0x40/0x40\nret_from_fork+0x34/0x80\n? __pfx_kthread+0x40/0x40\nret_from_fork_asm+0x1b/0x80\n\u003c/TASK\u003e\n\nConsidering that there may be holes in the CPU numbers, use the\nmaximum possible cpu number, instead of nr_cpu_ids, for configuring\nenqueue and dequeue limits.\n\n[ neeraj.upadhyay: Fix htmldocs build error reported by Stephen Rothwell ]","modified":"2026-04-02T12:21:08.109199Z","published":"2024-10-21T18:01:50.405Z","related":["USN-7276-1","USN-7277-1","openSUSE-SU-2024:14500-1","openSUSE-SU-2025:14705-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49926.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/05095271a4fb0f6497121a057f9a2edf386d5d96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3104bddc666ff64b90491868bbc4c7ebdd90aedf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b3b2431ed27f4ebc28e26cdf005c1de42dc60bdf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fd70e9f1d85f5323096ad313ba73f5fe3d15ea41"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49926.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-49926"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8610b65680390a103b58f46282a1b05f7eebbba4"},{"fixed":"b3b2431ed27f4ebc28e26cdf005c1de42dc60bdf"},{"fixed":"3104bddc666ff64b90491868bbc4c7ebdd90aedf"},{"fixed":"05095271a4fb0f6497121a057f9a2edf386d5d96"},{"fixed":"fd70e9f1d85f5323096ad313ba73f5fe3d15ea41"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49926.json"}}],"schema_version":"1.7.5"}