nfc: llcp: fix sdreq TLV list leak on parse/alloc/send failure

Overview

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

nfc: llcp: fix sdreq TLV list leak on parse/alloc/send failure

nfc_genl_llc_sdreq() builds a list of TLV nodes while walking nested netlink attrs, but 3 error paths (nested-attr parse failure, TLV alloc ENOMEM, nfc_llcp_send_snl_sdreq() failure) all skip freeing what was already queued.

Route them through a new free_list label, mirroring the SDRES path in the same file which already does this. Harmless on the success path too -- send_snl_sdreq() drains the list as it moves nodes, so it's already empty by the time free_list runs.

Affected

• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 5b1eca82085134bd92cd3810b0ef003c91e3f668
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < d3f60a7fc291d08cd9192a3b4cd5d3a223fa7d02
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 755bfc409748d8f3df64eb0eb26926270de3dd77
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < e43ec0191c1630f41e7043ac729ea6f1b8044a7f
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 08d2c069239ab425fdd333784a6a3b3e034e4aa0
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < cbde7f5d326172d6dbb55cca0df42fa7e1ed8115
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 0b01a946b0f234f5badd25968610b585a4895f08
• Linux >= d9b8d8e19b073096d3609bbd60f82148d128b555 < 66f4300206b82b0b143ef0d9be90cd8d29f23a47
• Linux 3.10

Remediation

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