Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
bna: prevent IOC timer rearm during teardown
bna: prevent IOC timer rearm during teardown
bnad_pci_remove() and the probe disable_ioceth path call timer_delete_sync() for ioc_timer, sem_timer and hb_timer, but not for iocpf_timer. bnad_iocpf_timeout() then takes bnad->bna_lock after free_netdev() has freed the struct bnad.
Deleting iocpf_timer last does not fix this. sem_timer and iocpf_timer rearm each other: bnad_iocpf_sem_timeout() can arm iocpf_timer, and bnad_iocpf_timeout() arms sem_timer from bfa_ioc_hw_sem_get() when the semaphore is busy. timer_delete_sync() only waits out its own callback. bnad_ioceth_disable() can time out and leave that callback live.
Shut all four IOC timers down with timer_shutdown_sync() on both paths, so a later mod_timer() is ignored.
This issue was identified during our ongoing static-analysis research while reviewing kernel code.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Ubuntu 26.04 | Planned | — |