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

igc: fix potential skb leak in igc_fpe_xmit_smd_frame()

When igc_fpe_init_tx_descriptor() fails, no one takes care of an allocated skb, leaking it. [1] Use dev_kfree_skb_any() on failure.

Tested on an I226 adapter with the following command, while injecting faults in igc_fpe_init_tx_descriptor() to trigger the error path.

ethtool –set-mm $DEV verify-enabled on tx-enabled on pmac-enabled on

[1] unreferenced object 0xffff888113c6cdc0 (size 224): … backtrace (crc be3d3fda): kmem_cache_alloc_node_noprof+0x3b1/0x410 __alloc_skb+0xde/0x830 igc_fpe_xmit_smd_frame.isra.0+0xad/0x1b0 igc_fpe_send_mpacket+0x37/0x90 ethtool_mmsv_verify_timer+0x15e/0x300

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/3ebf056556138e74c640e6dc2b3848abd398b460
• https://git.kernel.org/stable/c/e935c37b8a94bb256fada6395a5d05e1c0c6bdaf
• https://git.kernel.org/stable/c/f1bafd35f11b3aca1c7bb38da173b8787364a04c