Bug 2320552 (CVE-2024-49948)

Summary: CVE-2024-49948 kernel: net: add more sanity checks to qdisc_pkt_len_init()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2321040    
Bug Blocks:    

Description OSIDB Bzimport 2024-10-21 19:10:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: add more sanity checks to qdisc_pkt_len_init()

One path takes care of SKB_GSO_DODGY, assuming
skb->len is bigger than hdr_len.

virtio_net_hdr_to_skb() does not fully dissect TCP headers,
it only make sure it is at least 20 bytes.

It is possible for an user to provide a malicious 'GSO' packet,
total length of 80 bytes.

- 20 bytes of IPv4 header
- 60 bytes TCP header
- a small gso_size like 8

virtio_net_hdr_to_skb() would declare this packet as a normal
GSO packet, because it would see 40 bytes of payload,
bigger than gso_size.

We need to make detect this case to not underflow
qdisc_skb_cb(skb)->pkt_len.
Comment 1 Robb Gatica 2024-10-22 16:34:47 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102129-CVE-2024-49948-ba28@gregkh/T
Comment 2 Avinash Hanwate 2024-10-23 04:23:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102129-CVE-2024-49948-ba28@gregkh/T
Comment 3 Avinash Hanwate 2024-10-23 04:26:56 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102129-CVE-2024-49948-ba28@gregkh/T
Comment 4 errata-xmlrpc 2025-05-13 08:30:34 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966