CVE-2019-18807

Two memory leaks in the sja1105_static_config_upload() function in drivers/net/dsa/sja1105/sja1105_spi.c in the Linux kernel before 5.3.5 allow attackers to cause a denial of service (memory consumption) by triggering static_config_buf_prepare_for_upload() or sja1105_inhibit_tx() failures, aka CID-68501df92d11.

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://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.5
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=68501df92d116b760777a2cfda314789f926476f
• https://security.netapp.com/advisory/ntap-20191205-0001/