{"id":"CVE-2026-99192","aliases":[],"title":"net: bcmgenet: unshare the skb before writing the control block","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"40c04abcbc34e3afe338f41dae851ecbd72852ac","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"7939ad3b4db9eadf45a64f0524f38337a9494672","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"89771ce4f8f67dcffae561b2ccac95c0f6e3aa01","versionType":"git"},{"version":"fb4ca2b4bc6712a6ad635df5b9b41131846589f9","status":"affected","versionType":"git"},{"version":"3.16.50","status":"affected","lessThan":"3.17","versionType":"semver"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99192"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99192"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bcmgenet: unshare the skb before writing the control block\n\nbcmgenet stores first_cb, last_cb and bytes_sent in the skb control\nblock and reads them back on completion to free the skb and credit BQL.\nether_setup() leaves IFF_TX_SKB_SHARING set, so the stack can resubmit\na shared skb that is still in the ring. The next transmit overwrites\nlast_cb, so the earlier slots complete without crediting their bytes\nand BQL stalls the queue until the watchdog resets it.\n\nUnshare the skb before writing the control block.\n\nReproduce with pktgen in clone_skb mode, which hands the driver the same\nskb while earlier copies are still in the ring:\n\n  modprobe pktgen\n  pg=/proc/net/pktgen\n  echo \"add_device eth0\" > $pg/kpktgend_0\n  echo \"dst_mac AA:BB:CC:DD:EE:FF\" > $pg/eth0\n  echo \"dst 192.0.2.1\" > $pg/eth0\n  echo \"clone_skb 8\" > $pg/eth0\n  echo \"count 0\" > $pg/eth0\n  echo start > $pg/pgctrl &\n  sleep 5\n  echo stop > $pg/pgctrl\n  wait\n  cat /sys/class/net/eth0/queues/tx-0/byte_queue_limits/inflight\n\ninflight stays nonzero on the now idle queue. clone_skb 0 leaves it at\nzero.","severity":"unknown","score":null,"published":"2026-10-28T10:35:48.686Z","modified":"2026-10-28T10:35:48.686Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac","https://git.kernel.org/stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672","https://git.kernel.org/stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01"],"sources":[{"name":"CVE","id":"CVE-2026-99192","modified":"2026-10-28T10:35:48.686Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99192"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T04:10:31.984Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}