Linux Kernel Daily: The rc4 Hardening Wave
This cycle's rc4 pulls were dominated by use-after-free and memory-safety fixes across nine subsystems, with the SMB client stack standing out for closing multiple bugs reachable by a malicious server. No single feature stands above the pack; the pattern is broad defensive cleanup ahead of release.
Duration: PT2M26S
Episode overview
This episode is a short developer briefing from Linux Kernel Daily.
It explains recent repository work in plain language.
- Show: Linux Kernel Daily
- Published: 2026-09-19T06:02:20Z
- Audio duration: PT2M26S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
It's September 19th, 2026, and this is Linux Kernel Daily.
The signal today isn't any one feature, it's the sheer volume of use-after-free and bounds-checking fixes landing together across completely unrelated subsystems, all part of the run-up to release.
Start with the SMB client, pulled by Linus in commit 17e7b8e. This is the standout theme: multiple out-of-bounds reads and use-after-frees in the receive path that are reachable from a malicious or compromised server. That includes a stale buffer pointer and integer overflow in encrypted compound frames, missing…
The same use-after-free pattern shows up almost everywhere else. MMC's hsq and mmci drivers both fixed use-after-frees in retry and busy-timeout work. Hwmon fixed use-after-frees in w83793, w83791d, and the HP WMI sensors driver. Watchdog and SoC pulls each closed reference-counting and leak issues, including one in…
Second theme: input validation at driver boundaries. SCSI's core fix, in 925724c, validates mode sense buffer lengths because a specially crafted USB device could exploit ATA through that path. AMD's KFD driver fixed integer underflow in ring size calculations. These are the same class of bug as the SMB…
The…
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