CVE-2026-98555 PUBLISHED

llc: fix skb UAF and leaks on llc_mac_hdr_init() failure

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

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

llc: fix skb UAF and leaks on llc_mac_hdr_init() failure

In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init() fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu), and double-frees skb when llc_conn_state_process() drops its reference.

In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is leaked if llc_mac_hdr_init() returns an error.

Free nskb in all three error paths.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to fec0fe6838a7f45175667701fb51abb23a6ffb1e (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to b859ba18b5a1067f71db5618c6a4a70d55fa308b (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 8b855b645841b5a04e20339a22bb6d593c9b790d (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to d360b31f1a3666579422872aa7d1a751e20b76f9 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 060f827aa3dc47939ee306da715cd6700d129616 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 41dcae82bece9f106b4dff0ee777bba8d157c8a8 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to cb3528ad8bb46fa6252f5d14ced7febddc18515d (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 72f9dd522f8d6c5a00be9695c7bb74631eb5069e (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 2.6.12 is affected
  • unaffected from 0 to 2.6.12 (excl.)
  • unaffected from 5.10.271 to 5.10.* (incl.)
  • unaffected from 5.15.222 to 5.15.* (incl.)
  • unaffected from 6.1.189 to 6.1.* (incl.)
  • unaffected from 6.6.158 to 6.6.* (incl.)
  • unaffected from 6.12.112 to 6.12.* (incl.)
  • unaffected from 6.18.55 to 6.18.* (incl.)
  • unaffected from 7.2.9 to 7.2.* (incl.)
  • unaffected from 7.3-rc5 to * (incl.)

References