{"id":"CVE-2026-98039","published":"2026-09-25T11:17:32.663","lastModified":"2026-09-25T11:17:32.663","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Require MEM_PERCPU for percpu kptr stores\n\nmap_kptr_match_type() treats perm_flags as the set of register type flags\nthat a kptr field permits. Adding MEM_PERCPU to that set for\nBPF_KPTR_PERCPU does not require the source register to carry it, however.\nThe subset test consequently accepts both a plain bpf_obj_new() allocation\nand a referenced kernel pointer into a __percpu_kptr map field.\n\nLoads from the field are always marked MEM_PERCPU. Consumers then treat the\nstored value as the cookie returned by bpf_percpu_obj_new(): per-CPU pointer\nhelpers relocate it, and map teardown selects the per-CPU free path. A plain\nallocation can therefore provide an arbitrary kernel read/write, while a\nkernel pointer can be relocated into an invalid address or sent through a\nmissing destructor.\n\nRequire the source MEM_PERCPU flag to match the destination field kind.\nThis preserves valid bpf_percpu_obj_new() stores and rejects both the\nprogram-BTF and kernel-BTF variants.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/048029ba1c793f8cabc4ad5eea765da01903f8f1","tags":[]},{"url":"https://git.kernel.org/stable/c/0bdd6121c8dd5f1764efe701ce26bb8e15acb172","tags":[]},{"url":"https://git.kernel.org/stable/c/aaa9cf7707d1c5c0d2ca9d40c8b71652ac1c3c3f","tags":[]},{"url":"https://git.kernel.org/stable/c/ad4ebae5dbc2d47b544aa54f03c12490065be08a","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}