Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: kcm: Fix race condition in kcm_unattach()
syzbot found a race condition when kcm_unattach(psock) and kcm_release(kcm) are executed at the same time.
kcm_unattach() is missing a check of the flag kcm->tx_stopped before calling queue_work().
If the kcm has a reserved psock, kcm_unattach() might get executed between cancel_work_sync() and unreserve_psock() in kcm_release(), requeuing kcm->tx_work right before kcm gets freed in kcm_done().
Remove kcm->tx_stopped and replace it by the less error-prone disable_work_sync().
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
net: kcm: Fix race condition in kcm_unattach()
syzbot found a race condition when kcm_unattach(psock) and kcm_release(kcm) are executed at the same time.
kcm_unattach() is missing a check of the flag kcm->tx_stopped before calling queue_work().
If the kcm has a reserved psock, kcm_unattach() might get executed between cancel_work_sync() and unreserve_psock() in kcm_release(), requeuing kcm->tx_work right before kcm gets freed in kcm_done().
Remove kcm->tx_stopped and replace it by the less error-prone disable_work_sync().