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CVE-2024-49979

MEDIUMCVSS 5.5/10EPSS 0.23%

Last modified

CVE-2024-49979 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.23%

13.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.10, < 6.10.14—
LinuxLinux Kernel>= 6.11, < 6.11.3—
LinuxLinux Kernel6.12Rc1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2024-49979?
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.
How severe is CVE-2024-49979?
CVE-2024-49979 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.
How do I fix CVE-2024-49979?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-49979?

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Source: NVD / NIST