CVE-2026-98074bonding: do not clear curr_active_slave prematurely when releasing all slaves

Official description

In the Linux kernel, the following vulnerability has been resolved: bonding: do not clear curr_active_slave prematurely when releasing all slaves When releasing all slaves during bond destruction (all == true), __bond_release_one() unconditionally clears bond->curr_active_slave to NULL in every iteration. If a backup slave is released before the active slave, bond_alb_deinit_slave() triggers rlb_teach_disabled_mac_on_primary(), which increments the active slave dev promiscuity counter and sets bond_info->primary_is_promisc = 1. Because bond->curr_active_slave was prematurely cleared to NULL when releasing the backup slave, the subsequent iteration releasing the active slave evaluates oldcurrent as NULL, so bond_change_active_slave(bond, NULL) is skipped. Consequently, bond_alb_handle_active_change() is never called to decrement the promiscuity counter, permanently leaking promiscuous mode on the physical device after bond teardown. When oldcurrent == slave, bond_change_active_slave(bond, NULL) already sets bond->curr_active_slave to NULL. We only need to avoid selecting a new active slave when all == true. Replace the if (all) branch with if (!all && oldcurrent == slave).

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/b1ded242135071769902778dbab081e3fc09730f
• https://git.kernel.org/stable/c/e39b203ec9e73852098d41b26386172d51babeb9
• https://git.kernel.org/stable/c/384739c631aa6749356ba062d6b7c9a484a733f6
• https://git.kernel.org/stable/c/7b435c69a30b40efc642de98b9bfa95fcf2ad4f0
• https://git.kernel.org/stable/c/d6ef22e79c2be3612868daede0e9a84f05439d9e
• https://git.kernel.org/stable/c/19ba7ecfade159b3702c78a360fd7d971e2b7109
• https://git.kernel.org/stable/c/6d0ee411d5437f3d126ea6979acb83a8da29dc81
• https://git.kernel.org/stable/c/af602c7aa5fedc9be3043244017aef4f26c96b70