CVE-2025-68362

In the Linux kernel, the following vulnerability has been resolved:

wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187_rx_cb()

The rtl8187_rx_cb() calculates the rx descriptor header address by subtracting its size from the skb tail pointer. However, it does not validate if the received packet (skb->len from urb->actual_length) is large enough to contain this header.

If a truncated packet is received, this will lead to a buffer underflow, reading memory before the start of the skb data area, and causing a kernel panic.

Add length checks for both rtl8187 and rtl8187b descriptor headers before attempting to access them, dropping the packet cleanly if the check fails.

Affected Software

References

• https://git.kernel.org/stable/c/4758770a673c60d8f615809304d72e1432fa6355
• https://git.kernel.org/stable/c/5ebf0fe7eaef9f6173a4c6ea77c5353e21645d15
• https://git.kernel.org/stable/c/638d4148e166d114a4cd7becaae992ce1a815ed8
• https://git.kernel.org/stable/c/b647d2574e4583c2e3b0ab35568f60c88e910840