Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: fec: remove .ndo_poll_controller to avoid deadlocks
There is a deadlock issue found in sungem driver, please refer to the commit ac0a230f719b (“eth: sungem: remove .ndo_poll_controller to avoid deadlocks”). The root cause of the issue is that netpoll is in atomic context and disable_irq() is called by .ndo_poll_controller interface of sungem driver, however, disable_irq() might sleep. After analyzing the implementation of fec_poll_controller(), the fec driver should have the same issue. Due to the fec driver uses NAPI for TX completions, the .ndo_poll_controller is unnecessary to be implemented in the fec driver, so fec_poll_controller() can be safely removed.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- linux @ 4.4.0 (+12 more)
In the Linux kernel, the following vulnerability has been resolved:
net: fec: remove .ndo_poll_controller to avoid deadlocks
There is a deadlock issue found in sungem driver, please refer to the commit ac0a230f719b (“eth: sungem: remove .ndo_poll_controller to avoid deadlocks”). The root cause of the issue is that netpoll is in atomic context and disable_irq() is called by .ndo_poll_controller interface of sungem driver, however, disable_irq() might sleep. After analyzing the implementation of fec_poll_controller(), the fec driver should have the same issue. Due to the fec driver uses NAPI for TX completions, the .ndo_poll_controller is unnecessary to be implemented in the fec driver, so fec_poll_controller() can be safely removed.