{"apiVersion":"1.0","identifier":"CVE-2026-74726","description":"In the Linux kernel, the following vulnerability has been resolved: bonding: alb: re-check primary_is_promisc under RTNL in bond_alb_monitor bond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and takes RTNL via rtnl_trylock() before undoing the promiscuity it set on the active slave. In that window the active slave can change under RTNL (RTM_DELLINK -> __bond_release_one() -> bond_alb_handle_active_change()), which already drops the promiscuity and clears primary_is_promisc. The monitor still acts on the stale decision: if the slave was removed with no failover, curr_active_slave is now NULL and the deref faults; if it failed over, the stale dev_set_promiscuity(-1) underflows the new slave-s promiscuity counter and pins it in IFF_PROMISC. Oops: general protection fault, probably for non-canonical address ... KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] Workqueue: b42 bond_alb_monitor RIP: 0010:bond_alb_monitor (drivers/net/bonding/bond_alb.c:1600) process_one_work (kernel/workqueue.c:3322) worker_thread (kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) Kernel panic - not syncing: Fatal exception Re-check primary_is_promisc (and curr_active_slave) after taking RTNL so the monitor only undoes an increment it still owns. The other bonding monitors already re-read state under RTNL in their commit phase (bond_miimon_commit/bond_ab_arp_commit); bond_alb_monitor() was the only one acting on the pre-trylock decision.","publishedAt":"2026-08-22T16:16:47","lastModifiedAt":"2026-08-25T06:18:58","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74726","cvssScore":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","epssProbability":0.00126,"riskScore":0.74,"affectedProduct":"linux","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74726","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74726","en":"https://www.redsauce.net/en/cves/CVE-2026-74726","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74726","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74726","de":"https://www.redsauce.net/de/cves/CVE-2026-74726","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74726","el":"https://www.redsauce.net/el/cves/CVE-2026-74726"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74726"}}