CVE-2026-72339 qede: fix off-by-one in BD ring consumption on build_skb failure
An off-by-one error in the qede network driver can corrupt memory and cause system crashes or potential code execution under memory pressure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72339?
CVE-2026-72339 is a critical memory corruption vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
qede: fix off-by-one in BD ring consumption on build_skb failure
qede_rx_build_skb() and qede_tpa_rx_build_skb() do not check for a NULL return from qede_build_skb(). When it returns NULL under memory pressure, the functions still consume a BD from the ring before returning NULL. The callers then recycle additional BDs, resulting in one extra BD being consumed (off-by-one). This desynchronizes the BD ring, which can corrupt DMA page reference counts and lead to SLUB freelist corruption.
Commit 4e910dbe3650 ("qede: confirm skb is allocated before using") added a NULL check inside qede_build_skb() to prevent a NULL pointer dereference, but did not address the missing NULL checks in the callers, making this off-by-one reachable.
Fix this by adding NULL checks for the return value of qede_build_skb() in both qede_rx_build_skb() and qede_tpa_rx_build_skb(), returning NULL immediately before any BD ring manipulation.
Which versions are affected by CVE-2026-72339?
How do I fix CVE-2026-72339?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72339 being exploited?
There is no known exploitation of CVE-2026-72339 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72339, DEBIAN-CVE-2026-72339, GHSA-447g-7f2j-g4vp, UBUNTU-CVE-2026-72339.