CVE-2026-72339
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
In the Linux kernel's qede driver, there is an off-by-one error in BD ring consumption when skb building fails. The functions qede_rx_build_skb() and qede_tpa_rx_build_skb() do not check for a NULL return from qede_build_skb(), leading to excessive BD consumption and desynchronization of the BD ring, which can corrupt DMA page reference counts and cause SLUB freelist corruption.
Risk Assessment
The vulnerability can lead to kernel memory corruption, potentially causing system crashes or privilege escalation. However, it requires memory pressure conditions, limiting risk under normal operation.
Recommendation
Apply the Linux kernel patch that adds missing NULL checks in the qede_build_skb() callers immediately. Also monitor security updates from your distribution.
Original NVD description (English source)
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.