{"id":"CVE-2026-98787","title":"bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()\n\nbpf_mem_cache_free_rcu() uses this_cpu_ptr() which requires migration\nto be disabled. Al…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 818e0084822742fc00eacbf5df3476a5e72c7d0e < 94f41ec5fa578765b74ad5736c2f029e7aabc46d","Linux >= 818e0084822742fc00eacbf5df3476a5e72c7d0e < de020dc8049bfb2b22e3b6d99c031feb2e22d112","Linux 7.2"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:48:23.947Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98787","references":[{"url":"https://git.kernel.org/stable/c/94f41ec5fa578765b74ad5736c2f029e7aabc46d"},{"url":"https://git.kernel.org/stable/c/de020dc8049bfb2b22e3b6d99c031feb2e22d112"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.486Z","slug":"CVE-2026-98787","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()\n\nbpf_mem_cache_free_rcu() uses this_cpu_ptr() which requires migration\nto be disabled. All callers of rhtab_delete_elem() disable migration\nexcept __rhtab_map_lookup_and_delete_batch(), which calls it under\nrcu_read_lock() only.\n\nOn CONFIG_PREEMPT_RCU, rcu_read_lock() does not disable preemption or\nmigration, so the task can migrate between CPUs during the delete loop,\ncausing this_cpu_ptr() to trigger:\n\n  BUG: using smp_processor_id() in preemptible [00000000] code\n\nFix by wrapping the delete loop in migrate_disable()/migrate_enable()\nin __rhtab_map_lookup_and_delete_batch(), matching the migration\nprotection that the other callers already provide.\n\n## Affected\n\n- `Linux >= 818e0084822742fc00eacbf5df3476a5e72c7d0e < 94f41ec5fa578765b74ad5736c2f029e7aabc46d`\n- `Linux >= 818e0084822742fc00eacbf5df3476a5e72c7d0e < de020dc8049bfb2b22e3b6d99c031feb2e22d112`\n- `Linux 7.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}