Bluetooth: bpa10x: avoid OOB read of revision string in bpa10x_setup()

Overview

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

Bluetooth: bpa10x: avoid OOB read of revision string in bpa10x_setup()

bpa10x_setup() sends the vendor command 0xfc0e and passes the response to bt_dev_info() and hci_set_fw_info() as a "%s" string starting at skb->data + 1, without checking the length:

bt_dev_info(hdev, "%s", (char *)(skb->data + 1));
hci_set_fw_info(hdev, "%s", skb->data + 1);

A device that returns a one-byte response (status only) leaves skb->data + 1 past the end of the data, and the %s walk reads adjacent slab memory until it meets a NUL. The same happens when the payload is not NUL-terminated within skb->len. The out-of-bounds bytes end up in the kernel log and the firmware-info debugfs file.

Print the revision string with a bounded "%.*s" limited to skb->len - 1 instead. This keeps the string readable for well-behaved devices while never reading past the received data, and does not fail setup, so a device returning a short or unterminated response keeps working.

Affected

• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < 1813add71e386f77b3040e6c8dc9b7b3ff965a6c
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < bd56c23f1f8681a2857ee924a8bd3abf87c8913b
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < 7a64f39ebe1bacd9004a62eceadac0b122ec3cc2
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < f80b4afe893dffa9fabdbf80fb4d6782b24a6793
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < 4b4008dda1d0c6e598d7865631ad4eda63a560f0
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < bfc9e7be289df11e8e38c98cd78019d67fdd0bd5
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < a8e169d308775039200bb9c905c7ce420db6e8c5
• Linux >= ddd68ec8f4847b460c9f580076eafe13b031a6fd < dd068ef044128db655f48323a4acfd5907e04903
• Linux 4.4

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.