CVE-2026-98555
Published Oct 18, 2026
Description
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.
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References
Other References
https://git.kernel.org/stable/c/060f827aa3dc47939ee306da715cd6700d129616
https://git.kernel.org/stable/c/41dcae82bece9f106b4dff0ee777bba8d157c8a8
https://git.kernel.org/stable/c/72f9dd522f8d6c5a00be9695c7bb74631eb5069e
https://git.kernel.org/stable/c/8b855b645841b5a04e20339a22bb6d593c9b790d
https://git.kernel.org/stable/c/b859ba18b5a1067f71db5618c6a4a70d55fa308b
https://git.kernel.org/stable/c/cb3528ad8bb46fa6252f5d14ced7febddc18515d
https://git.kernel.org/stable/c/d360b31f1a3666579422872aa7d1a751e20b76f9
https://git.kernel.org/stable/c/fec0fe6838a7f45175667701fb51abb23a6ffb1e
Frequently Asked Questions
What is CVE-2026-98555? +
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.
How do I check if I'm vulnerable to CVE-2026-98555? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.