In the Linux kernel, the following vulnerability has been resolved: wifi: p54: validate RX frame length in p54_rx_eeprom_readback() p54_rx

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

wifi: p54: validate RX frame length in p54_rx_eeprom_readback()

p54_rx_eeprom_readback() copies the requested EEPROM slice out of a
device-supplied readback frame without checking that the skb actually holds
that many bytes. Commit da1b9a55ff11 ("wifi: p54: prevent buffer-overflow in
p54_rx_eeprom_readback()") closed the destination overflow by copying a
fixed priv->eeprom_slice_size (and rejecting a mismatched advertised len),
but the source side is still unbounded: nothing verifies the frame is long
enough to supply that many bytes.

A malicious USB device can send a short frame whose advertised len matches
priv->eeprom_slice_size while the payload is truncated. The equality check
passes and memcpy() reads past the end of the skb, leaking adjacent heap:

BUG: KASAN: slab-out-of-bounds in p54_rx (drivers/net/wireless/intersil/p54/txrx.c:507)
Read of size 1016 at addr ffff88800f077114 by task swapper/0/0
Call Trace:
<IRQ>
...
__asan_memcpy (mm/kasan/shadow.c:105)
p54_rx (drivers/net/wireless/intersil/p54/txrx.c:507)
p54u_rx_cb (drivers/net/wireless/intersil/p54/p54usb.c:163)
__usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1657)
dummy_timer (drivers/usb/gadget/udc/dummy_hcd.c:2005)
...
</IRQ>

The buggy address belongs to the object at ffff88800f0770c0
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 84 bytes inside of
allocated 704-byte region [ffff88800f0770c0, ffff88800f077380)

Check that the slice fits in the skb before copying.