CVE-2026-98555

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

State: Published
Severity: 7.5 High
Published: Oct 18, 2026
Updated: Oct 24, 2026
Reserved: Sep 25, 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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before fec0fe6838a7f45175667701fb51abb23a6ffb1eAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b859ba18b5a1067f71db5618c6a4a70d55fa308bAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 8b855b645841b5a04e20339a22bb6d593c9b790dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d360b31f1a3666579422872aa7d1a751e20b76f9Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 060f827aa3dc47939ee306da715cd6700d129616Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 41dcae82bece9f106b4dff0ee777bba8d157c8a8Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before cb3528ad8bb46fa6252f5d14ced7febddc18515dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 72f9dd522f8d6c5a00be9695c7bb74631eb5069eAffected
LinuxLinux	2.6.12Affected before 2.6.12Not affected 5.10.271 through 5.10.Not affected 5.15.222 through 5.15.Not affected 6.1.189 through 6.1.Not affected 6.6.158 through 6.6.Not affected 6.12.112 through 6.12.Not affected 6.18.55 through 6.18.Not affected 7.2.9 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before fec0fe6838a7f45175667701fb51abb23a6ffb1eAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b859ba18b5a1067f71db5618c6a4a70d55fa308bAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 8b855b645841b5a04e20339a22bb6d593c9b790dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d360b31f1a3666579422872aa7d1a751e20b76f9Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 060f827aa3dc47939ee306da715cd6700d129616Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 41dcae82bece9f106b4dff0ee777bba8d157c8a8Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before cb3528ad8bb46fa6252f5d14ced7febddc18515dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 72f9dd522f8d6c5a00be9695c7bb74631eb5069eAffected

LinuxLinux

2.6.12Affected
before 2.6.12Not affected
5.10.271 through 5.10.*Not affected
5.15.222 through 5.15.*Not affected
6.1.189 through 6.1.*Not affected
6.6.158 through 6.6.*Not affected
6.12.112 through 6.12.*Not affected
6.18.55 through 6.18.*Not affected
7.2.9 through 7.2.*Not affected
7.3 and laterNot affected

References

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