{"id":"CVE-2026-74726","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: re-check primary_is_promisc under RTNL in bond_alb_monitor\n\nbond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and\ntakes RTNL via rtnl_…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: re-check primary_is_promisc under RTNL in bond_alb_monitor\n\nbond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and\ntakes RTNL via rtnl_…","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","published":"2026-08-22","updated":"2026-10-14","sourceUpdated":"2026-10-14T13:10:00.187","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74726","references":[{"url":"https://git.kernel.org/stable/c/09add8d5cfa9c46828f51eaad162c36e86366b71","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/257c4a3a34d8f51efb00f35375a0c6ce3c8f6ce2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2faf75a8a06504071b4c0aea7e45a9cc49a4e187","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/683c6ba6e58e6ed1037831ea97dd58d9c0e76b8d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b82f51681a7a88c7d3c865e817a3340d42b5fa2a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dccec0227ed8d9e36936d66e256b957dc2858468","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dd148539fb4741d01c06b7d2c8bd84b01920756c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f7668762bf5fd6db9397de5c0514407489d9d815","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00126,"epssPercentile":0.02024,"ingestedAt":"2026-10-14T13:30:58.549Z","slug":"CVE-2026-74726","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: re-check primary_is_promisc under RTNL in bond_alb_monitor\n\nbond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and\ntakes RTNL via rtnl_trylock() before undoing the promiscuity it set on the\nactive slave. In that window the active slave can change under RTNL\n(RTM_DELLINK -> __bond_release_one() -> bond_alb_handle_active_change()),\nwhich already drops the promiscuity and clears primary_is_promisc. The\nmonitor still acts on the stale decision: if the slave was removed with no\nfailover, curr_active_slave is now NULL and the deref faults; if it failed\nover, the stale dev_set_promiscuity(-1) underflows the new slave's\npromiscuity counter and pins it in IFF_PROMISC.\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n  Workqueue: b42 bond_alb_monitor\n  RIP: 0010:bond_alb_monitor (drivers/net/bonding/bond_alb.c:1600)\n   process_one_work (kernel/workqueue.c:3322)\n   worker_thread (kernel/workqueue.c:3486)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n  Kernel panic - not syncing: Fatal exception\n\nRe-check primary_is_promisc (and curr_active_slave) after taking RTNL so\nthe monitor only undoes an increment it still owns. The other bonding\nmonitors already re-read state under RTNL in their commit phase\n(bond_miimon_commit/bond_ab_arp_commit); bond_alb_monitor() was the only\none acting on the pre-trylock decision.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}