{"id":"CVE-2026-98881","state":"PUBLISHED","title":"net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: remove stale rcu_barrier() in br_multicast_dev_del()\n\nThis rcu_barrier() came from a time call_rcu() calls were used in\nnet/bridge/br_multicast.c.\n\nNow kfree_rcu() is there, we can remove this problematic rcu_barrier()\nwhich causes extreme RTNL pressure in many syzbot reports.\n\nINFO: task syz-executor:77945 is blocked on a mutex likely owned by task kworker/u1024:5:36537.\ntask:kworker/u1024:5 state:D stack:24616 pid:36537 tgid:36537 ppid:2      task_flags:0x4208060 flags:0x00080000 last_sleep:612797637337\nWorkqueue: netns cleanup_net\nCall Trace:\n <TASK>\n  [<ffffffff81914eaa>] context_switch+0xf2a/0x1730 kernel/sched/core.c:6483\n  [<ffffffff81201143>] __schedule+0x1133/0x43a0 kernel/sched/core.c:8411\n  [<ffffffff8120446b>] __schedule_loop kernel/sched/core.c:8514 [inline]\n  [<ffffffff8120446b>] schedule+0xab/0x260 kernel/sched/core.c:8529\n  [<ffffffff8121a093>] schedule_timeout+0xc3/0x2b0 kernel/time/sleep_timeout.c:75\n  [<ffffffff81205347>] do_wait_for_common kernel/sched/completion.c:100 [inline]\n  [<ffffffff81205347>] __wait_for_common kernel/sched/completion.c:121 [inline]\n  [<ffffffff81205347>] wait_for_common kernel/sched/completion.c:132 [inline]\n  [<ffffffff81205347>] wait_for_completion+0x2c7/0x5d0 kernel/sched/completion.c:153\n  [<ffffffff81b8f27f>] rcu_barrier+0x49f/0x620 kernel/rcu/tree.c:3888\n  [<ffffffff860091b3>] br_multicast_dev_del+0x303/0x350 net/bridge/br_multicast.c:4459\n  [<ffffffff85fb5dbc>] br_dev_uninit+0x1c/0x40 net/bridge/br_device.c:157\n  [<ffffffff8568058c>] unregister_netdevice_many_notify+0x1c1c/0x2300 net/core/dev.c:12599\n  [<ffffffff8562be43>] ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]\n  [<ffffffff8562be43>] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248","publishedAt":"2026-10-23T11:37:32.327Z","updatedAt":"2026-10-26T06:56:04.487Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"35f9f11740515a10b084adfb1ce691351f2452ab","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"0443f6aac6bf6a91e406273fdda11497cef6ad07","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"ac0e823a228f94ad9d7a3d876cc07e59a7afb806","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"f0018acf0b66f93a292667c9a9c2a26c570cf270","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"372ee8fbe0f796031c60f676ec90f0788c26523d","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"39679927fa7aaf4601119f7234342d1b5d4f6f84","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"25ae123db10ba9ab890b56bcdb0a4363aee8529a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_multicast.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_multicast.c"]}],"references":["https://git.kernel.org/stable/c/35f9f11740515a10b084adfb1ce691351f2452ab","https://git.kernel.org/stable/c/0443f6aac6bf6a91e406273fdda11497cef6ad07","https://git.kernel.org/stable/c/ac0e823a228f94ad9d7a3d876cc07e59a7afb806","https://git.kernel.org/stable/c/f0018acf0b66f93a292667c9a9c2a26c570cf270","https://git.kernel.org/stable/c/372ee8fbe0f796031c60f676ec90f0788c26523d","https://git.kernel.org/stable/c/39679927fa7aaf4601119f7234342d1b5d4f6f84","https://git.kernel.org/stable/c/25ae123db10ba9ab890b56bcdb0a4363aee8529a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98881.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98881","state":"PUBLISHED","datePublished":"2026-10-23T11:37:32.327Z","dateUpdated":"2026-10-26T06:56:04.487Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.378Z"},"containers":{"cna":{"title":"net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: remove stale rcu_barrier() in br_multicast_dev_del()\n\nThis rcu_barrier() came from a time call_rcu() calls were used in\nnet/bridge/br_multicast.c.\n\nNow kfree_rcu() is there, we can remove this problematic rcu_barrier()\nwhich causes extreme RTNL pressure in many syzbot reports.\n\nINFO: task syz-executor:77945 is blocked on a mutex likely owned by task kworker/u1024:5:36537.\ntask:kworker/u1024:5 state:D stack:24616 pid:36537 tgid:36537 ppid:2      task_flags:0x4208060 flags:0x00080000 last_sleep:612797637337\nWorkqueue: netns cleanup_net\nCall Trace:\n <TASK>\n  [<ffffffff81914eaa>] context_switch+0xf2a/0x1730 kernel/sched/core.c:6483\n  [<ffffffff81201143>] __schedule+0x1133/0x43a0 kernel/sched/core.c:8411\n  [<ffffffff8120446b>] __schedule_loop kernel/sched/core.c:8514 [inline]\n  [<ffffffff8120446b>] schedule+0xab/0x260 kernel/sched/core.c:8529\n  [<ffffffff8121a093>] schedule_timeout+0xc3/0x2b0 kernel/time/sleep_timeout.c:75\n  [<ffffffff81205347>] do_wait_for_common kernel/sched/completion.c:100 [inline]\n  [<ffffffff81205347>] __wait_for_common kernel/sched/completion.c:121 [inline]\n  [<ffffffff81205347>] wait_for_common kernel/sched/completion.c:132 [inline]\n  [<ffffffff81205347>] wait_for_completion+0x2c7/0x5d0 kernel/sched/completion.c:153\n  [<ffffffff81b8f27f>] rcu_barrier+0x49f/0x620 kernel/rcu/tree.c:3888\n  [<ffffffff860091b3>] br_multicast_dev_del+0x303/0x350 net/bridge/br_multicast.c:4459\n  [<ffffffff85fb5dbc>] br_dev_uninit+0x1c/0x40 net/bridge/br_device.c:157\n  [<ffffffff8568058c>] unregister_netdevice_many_notify+0x1c1c/0x2300 net/core/dev.c:12599\n  [<ffffffff8562be43>] ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]\n  [<ffffffff8562be43>] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"35f9f11740515a10b084adfb1ce691351f2452ab","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"0443f6aac6bf6a91e406273fdda11497cef6ad07","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"ac0e823a228f94ad9d7a3d876cc07e59a7afb806","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"f0018acf0b66f93a292667c9a9c2a26c570cf270","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"372ee8fbe0f796031c60f676ec90f0788c26523d","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"39679927fa7aaf4601119f7234342d1b5d4f6f84","versionType":"git"},{"version":"19e3a9c90c53479fecaa02307bf2db5ab8b3ffe3","status":"affected","lessThan":"25ae123db10ba9ab890b56bcdb0a4363aee8529a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_multicast.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_multicast.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/35f9f11740515a10b084adfb1ce691351f2452ab"},{"url":"https://git.kernel.org/stable/c/0443f6aac6bf6a91e406273fdda11497cef6ad07"},{"url":"https://git.kernel.org/stable/c/ac0e823a228f94ad9d7a3d876cc07e59a7afb806"},{"url":"https://git.kernel.org/stable/c/f0018acf0b66f93a292667c9a9c2a26c570cf270"},{"url":"https://git.kernel.org/stable/c/372ee8fbe0f796031c60f676ec90f0788c26523d"},{"url":"https://git.kernel.org/stable/c/39679927fa7aaf4601119f7234342d1b5d4f6f84"},{"url":"https://git.kernel.org/stable/c/25ae123db10ba9ab890b56bcdb0a4363aee8529a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-26T06:56:04.487Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}