CVE-2021-47453

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

ice: Avoid crash from unnecessary IDA free

In the remove path, there is an attempt to free the aux_idx IDA whether it was allocated or not. This can potentially cause a crash when unloading the driver on systems that do not initialize support for RDMA. But, this free cannot be gated by the status bit for RDMA, since it is allocated if the driver detects support for RDMA at probe time, but the driver can enter into a state where RDMA is not supported after the IDA has been allocated at probe time and this would lead to a memory leak.

Initialize aux_idx to an invalid value and check for a valid value when unloading to determine if an IDA free is necessary.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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/73e30a62b19b9fbb4e6a3465c59da186630d5f2e
• https://git.kernel.org/stable/c/777682e59840e24e6c5672197e6ffbcf4bff823b
• https://git.kernel.org/stable/c/73e30a62b19b9fbb4e6a3465c59da186630d5f2e
• https://git.kernel.org/stable/c/777682e59840e24e6c5672197e6ffbcf4bff823b