{"id":"CVE-2026-98787","state":"PUBLISHED","title":"bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()","description":"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. 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.","publishedAt":"2026-10-18T15:48:23.947Z","updatedAt":"2026-10-19T09:25:40.244Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"818e0084822742fc00eacbf5df3476a5e72c7d0e","status":"affected","lessThan":"94f41ec5fa578765b74ad5736c2f029e7aabc46d","versionType":"git"},{"version":"818e0084822742fc00eacbf5df3476a5e72c7d0e","status":"affected","lessThan":"de020dc8049bfb2b22e3b6d99c031feb2e22d112","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/hashtab.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.2","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/hashtab.c"]}],"references":["https://git.kernel.org/stable/c/94f41ec5fa578765b74ad5736c2f029e7aabc46d","https://git.kernel.org/stable/c/de020dc8049bfb2b22e3b6d99c031feb2e22d112"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98787.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98787","state":"PUBLISHED","datePublished":"2026-10-18T15:48:23.947Z","dateUpdated":"2026-10-19T09:25:40.244Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.370Z"},"containers":{"cna":{"title":"bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()","descriptions":[{"lang":"en","value":"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. 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"818e0084822742fc00eacbf5df3476a5e72c7d0e","status":"affected","lessThan":"94f41ec5fa578765b74ad5736c2f029e7aabc46d","versionType":"git"},{"version":"818e0084822742fc00eacbf5df3476a5e72c7d0e","status":"affected","lessThan":"de020dc8049bfb2b22e3b6d99c031feb2e22d112","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/hashtab.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.2","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/hashtab.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/94f41ec5fa578765b74ad5736c2f029e7aabc46d"},{"url":"https://git.kernel.org/stable/c/de020dc8049bfb2b22e3b6d99c031feb2e22d112"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:25:40.244Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.2","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.2","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}