CVE-2024-44971

In the Linux kernel, the following vulnerability has been resolved:

net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register()

bcm_sf2_mdio_register() calls of_phy_find_device() and then phy_device_remove() in a loop to remove existing PHY devices. of_phy_find_device() eventually calls bus_find_device(), which calls get_device() on the returned struct device * to increment the refcount. The current implementation does not decrement the refcount, which causes memory leak.

This commit adds the missing phy_device_free() call to decrement the refcount via put_device() to balance the refcount.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/7feef10768ea71d468d9bbc1e0d14c461876768c
• https://git.kernel.org/stable/c/a7d2808d67570e6acae45c2a96e0d59986888e4c
• https://git.kernel.org/stable/c/b7b8d9f5e679af60c94251fd6728dde34be69a71
• https://git.kernel.org/stable/c/c05516c072903f6fb9134b8e7e1ad4bffcdc4819
• https://git.kernel.org/stable/c/e3862093ee93fcfbdadcb7957f5f8974fffa806a
• https://git.kernel.org/stable/c/f3d5efe18a11f94150fee8b3fda9d62079af640a