Executive brief
A vulnerability was identified in the Linux kernel's D-Link network driver that could cause a system crash. The issue occurs when the system is under heavy load and fails to allocate memory for incoming network data, leading to a kernel panic. This primarily affects the availability of systems using specific D-Link network hardware, potentially causing unexpected downtime.
Technical details
A NULL pointer dereference exists in the Linux kernel D-Link dl2k network driver (drivers/net/ethernet/dlink/dl2k.c). The vulnerability is located in the receive_packet function, where the driver fails to check the return value of netdev_alloc_skb_ip_align() when attempting to allocate a socket buffer (skb) for small packets. If memory allocation fails, the driver proceeds to dereference the resulting NULL pointer when accessing skb->protocol. This can be triggered by network traffic under memory pressure conditions. The fix introduces proper error handling by falling back to the normal packet processing path if the small buffer allocation fails. Patches have been released for multiple stable kernel branches including 5.10.y, 5.15.y, 6.1.y, 6.6.y, and 6.12.y.
Affected products
- Linux Linux Kernel 2.6.12 to 6.12.53
Timeline
- 2025-09-29: patched: Initial fix committed to mainline kernel
- 2025-10-28: disclosed: CVE published
References
- https://git.kernel.org/stable/c/5aa9b885602811a026a3f45c92ea2b4b04c54f09
- https://git.kernel.org/stable/c/7ed5010fef0930f4322d620052edc854ef3ec41f
- https://git.kernel.org/stable/c/8169a6011c5fecc6cb1c3654c541c567d3318de8
- https://git.kernel.org/stable/c/84fd710a704f3d53d4120e452e86cea558cf73a8
- https://git.kernel.org/stable/c/9d49e4b14609e1a20d931e718962c4b6b5485174
- https://git.kernel.org/stable/c/ea87151df398d407a632c7bf63013290f01c5009
- https://git.kernel.org/stable/c/fd7b6b2c920d7fd370a612be416a904d6e1ebe55