{"id":"CVE-2026-99192","state":"PUBLISHED","title":"net: bcmgenet: unshare the skb before writing the control block","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.","publishedAt":"2026-10-28T10:35:48.686Z","updatedAt":"2026-10-30T12:42:50.060Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"c13d43c92bc89f494592a60e624a7c0c42218d36","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"e5aa07c62e4fda1206d314c9ea36d67cd6b95cad","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"2e5fb9dd3aca0da534793ad8123b81deff396efe","versionType":"git"},{"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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/genet/bcmgenet.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/genet/bcmgenet.c"]}],"references":["https://git.kernel.org/stable/c/c13d43c92bc89f494592a60e624a7c0c42218d36","https://git.kernel.org/stable/c/e5aa07c62e4fda1206d314c9ea36d67cd6b95cad","https://git.kernel.org/stable/c/2e5fb9dd3aca0da534793ad8123b81deff396efe","https://git.kernel.org/stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac","https://git.kernel.org/stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672","https://git.kernel.org/stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99192.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99192","state":"PUBLISHED","datePublished":"2026-10-28T10:35:48.686Z","dateUpdated":"2026-10-30T12:42:50.060Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.400Z"},"containers":{"cna":{"title":"net: bcmgenet: unshare the skb before writing the control block","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"c13d43c92bc89f494592a60e624a7c0c42218d36","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"e5aa07c62e4fda1206d314c9ea36d67cd6b95cad","versionType":"git"},{"version":"f48bed16a756f5bc0244acd581f61968f7d7c2a4","status":"affected","lessThan":"2e5fb9dd3aca0da534793ad8123b81deff396efe","versionType":"git"},{"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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/genet/bcmgenet.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","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"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/genet/bcmgenet.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c13d43c92bc89f494592a60e624a7c0c42218d36"},{"url":"https://git.kernel.org/stable/c/e5aa07c62e4fda1206d314c9ea36d67cd6b95cad"},{"url":"https://git.kernel.org/stable/c/2e5fb9dd3aca0da534793ad8123b81deff396efe"},{"url":"https://git.kernel.org/stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac"},{"url":"https://git.kernel.org/stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672"},{"url":"https://git.kernel.org/stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:42:50.060Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16.50"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}