nfc: llcp: fix slab-out-of-bounds reads when logging service names

Overview

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

nfc: llcp: fix slab-out-of-bounds reads when logging service names

nfc_llcp_wks_sap() and nfc_llcp_build_sdreq_tlv() pass non-null- terminated strings to pr_debug() using the %s format specifier. The buffers are allocated via kmemdup() or come from netlink attributes and are not guaranteed to be null-terminated, causing __dynamic_pr_debug() to read beyond the allocated region:

KASAN: slab-out-of-bounds Read in __dynamic_pr_debug

Fix both call sites by using %.*s with the explicit length to limit the output to the actual length of the string.

Affected

• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 75f7c5a42fa1483f5912279a749417c284ad708f
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 6d4ca872830e46fcca9c086bf19fa9bd2faf09d2
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < a143f7835faa4fe0178448289feea4f84eeee8d6
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 75bfd9ef4da2fb49dac1f19880d2ac4ccd07b45b
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 8afb6c194f5781798d3ab3edf243cf5a24a9d1f9
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 8978dff632519712d1fa432991e1f2e857f90239
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 4262b12277a3e056c95fc49e9c4d7bd97035d16c
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 7dcf371a35632f035baf77bcf2c129165f772ce4
• Linux 3.10

Remediation

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