CVE-2026-31660

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: pn533: allocate rx skb before consuming bytes pn532_receive_buf() reports the number of accepted bytes to the serdev core. The current code consumes bytes into recv_skb and may already hand a complete frame to pn533_recv_frame() before allocating a fresh receive buffer. If that alloc_skb() fails, the callback returns 0 even though it has already consumed bytes, and it leaves recv_skb as NULL for the next receive callback. That breaks the receive_buf() accounting contract and can also lead to a NULL dereference on the next skb_put_u8(). Allocate the receive skb lazily before consuming the next byte instead. If allocation fails, return the number of bytes already accepted.

References

• https://git.kernel.org/stable/c/07cb6c72e66ba548679f22ac29ad588da8999279
• https://git.kernel.org/stable/c/16649adc2e19509104245ea1f349b629d858f11f
• https://git.kernel.org/stable/c/21ae2cda66a55c759607bbf1d23cbaa42019d2de
• https://git.kernel.org/stable/c/2ca64fb7e2d2ae14619dd204d4f2f0a601f421fb
• https://git.kernel.org/stable/c/7e37da42eda45d7859d9273fc7e225d8df458038