CVE-2024-49979
Published: October 23, 2024Last modified: October 23, 2024
Description
In the Linux kernel, the following vulnerability has been resolved: net: gso: fix tcp fraglist segmentation after pull from frag_list Detect tcp gso fraglist skbs with corrupted geometry (see below) and pass these to skb_segment instead of skb_segment_list, as the first can segment them correctly. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify these skbs, breaking these invariants. In extreme cases they pull all data into skb linear. For TCP, this causes a NULL ptr deref in __tcpv4_gso_segment_list_csum at tcp_hdr(seg->next). Detect invalid geometry due to pull, by checking head_skb size. Don't just drop, as this may blackhole a destination. Convert to be able to pass to regular skb_segment. Approach and description based on a patch by Willem de Bruijn.
Severity score breakdown
Parameter | Value |
---|---|
Base score | 5.5 |
Attack Vector | LOCAL |
Attack complexity | LOW |
Privileges required | LOW |
User interaction | NONE |
Scope | UNCHANGED |
Confidentiality | NONE |
Integrity impact | NONE |
Availability impact | HIGH |
Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
Product | Release | Package | Status |
---|---|---|---|
Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.33-r0) |
25 LTS | linux-lts | Fixed (6.12.41-r0) | |
Stream | linux-lts | Fixed (6.12.41-r0) |