net: systemport: Fix buffer overflow in bcm_sysport_get_stats()

Overview

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

net: systemport: Fix buffer overflow in bcm_sysport_get_stats()

When running on SYSTEMPORT Lite, certain statistics are unsupported and skipped during bcm_sysport_get_stats(). The variable 'j' tracks the compacted index into the destination data buffer, whereas 'i' iterates over all elements in bcm_sysport_gstrings_stats.

Because the buffer allocated by ethtool is sized only according to bcm_sysport_get_sset_count(), storing values at data[i] instead of data[j] writes past the allocated array bounds, leading to memory corruption.

Fix this by writing to data[j] instead of data[i].

Affected

• Linux >= 10377ba7673d19e28d92846955d51f49acd25c35 < 29d1d35ad5ad379a904263ea1cd4ba1d71cd965f
• Linux >= 10377ba7673d19e28d92846955d51f49acd25c35 < 96d8b26be5bc451188acdcee055948da45adbde0
• Linux >= 10377ba7673d19e28d92846955d51f49acd25c35 < faba9fdde480356f4a1d3b1a5713b7b354858a1c
• Linux >= 10377ba7673d19e28d92846955d51f49acd25c35 < eb7b84af0ec5c71b4920e999611b466b3784496c
• Linux 4.14

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.