Improper Input Validation Affecting kernel-debug package, versions <0:4.18.0-305.139.1.el8_4

Note: Versions mentioned in the description apply only to the upstream kernel-debug package and not the kernel-debug package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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

tun: add missing verification for short frame

The cited commit missed to check against the validity of the frame length in the tun_xdp_one() path, which could cause a corrupted skb to be sent downstack. Even before the skb is transmitted, the tun_xdp_one-->eth_type_trans() may access the Ethernet header although it can be less than ETH_HLEN. Once transmitted, this could either cause out-of-bound access beyond the actual length, or confuse the underlayer with incorrect or inconsistent header length in the skb metadata.

In the alternative path, tun_get_user() already prohibits short frame which has the length less than Ethernet header size from being transmitted for IFF_TAP.

This is to drop any frame shorter than the Ethernet header size just like how tun_get_user() does.

CVE: CVE-2024-41091

• https://access.redhat.com/security/cve/CVE-2024-41091
• https://git.kernel.org/stable/c/049584807f1d797fc3078b68035450a9769eb5c3
• https://git.kernel.org/stable/c/32b0aaba5dbc85816898167d9b5d45a22eae82e9
• https://git.kernel.org/stable/c/589382f50b4a5d90d16d8bc9dcbc0e927a3e39b2
• https://git.kernel.org/stable/c/6100e0237204890269e3f934acfc50d35fd6f319
• https://git.kernel.org/stable/c/8418f55302fa1d2eeb73e16e345167e545c598a5
• https://git.kernel.org/stable/c/a9d1c27e2ee3b0ea5d40c105d6e728fc114470bb
• https://git.kernel.org/stable/c/ad6b3f622ccfb4bfedfa53b6ebd91c3d1d04f146
• https://git.kernel.org/stable/c/d5ad89b7d01ed4e66fd04734fc63d6e78536692a