Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: Correct check for empty list
Since commit a3c53be55c95 (“net: dsa: mv88e6xxx: Support multiple MDIO busses”) mv88e6xxx_default_mdio_bus() has checked that the return value of list_first_entry() is non-NULL.
This appears to be intended to guard against the list chip->mdios being empty. However, it is not the correct check as the implementation of list_first_entry is not designed to return NULL for empty lists.
Instead, use list_first_entry_or_null() which does return NULL if the list is empty.
Flagged by Smatch. Compile tested only.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: Correct check for empty list
Since commit a3c53be55c95 (“net: dsa: mv88e6xxx: Support multiple MDIO busses”) mv88e6xxx_default_mdio_bus() has checked that the return value of list_first_entry() is non-NULL.
This appears to be intended to guard against the list chip->mdios being empty. However, it is not the correct check as the implementation of list_first_entry is not designed to return NULL for empty lists.
Instead, use list_first_entry_or_null() which does return NULL if the list is empty.
Flagged by Smatch. Compile tested only.