Bug 2396145 (CVE-2022-50365)

Summary: CVE-2022-50365 kernel: Linux kernel: Local denial of service in skbuff due to improper network buffer handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. A local user with low privileges could trigger a kernel bug by manipulating network packet buffer (skbuff) operations. Specifically, when a program uses a helper function to read data beyond the allocated buffer in certain Generic Segmentation Offload (GSO) scenarios, it can lead to an unexpected system crash. This vulnerability results in a Denial of Service (DoS).
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Description OSIDB Bzimport 2025-09-17 15:03:58 UTC 
In the Linux kernel, the following vulnerability has been resolved:

skbuff: Account for tail adjustment during pull operations

Extending the tail can have some unexpected side effects if a program uses
a helper like BPF_FUNC_skb_pull_data to read partial content beyond the
head skb headlen when all the skbs in the gso frag_list are linear with no
head_frag -

  kernel BUG at net/core/skbuff.c:4219!
  pc : skb_segment+0xcf4/0xd2c
  lr : skb_segment+0x63c/0xd2c
  Call trace:
   skb_segment+0xcf4/0xd2c
   __udp_gso_segment+0xa4/0x544
   udp4_ufo_fragment+0x184/0x1c0
   inet_gso_segment+0x16c/0x3a4
   skb_mac_gso_segment+0xd4/0x1b0
   __skb_gso_segment+0xcc/0x12c
   udp_rcv_segment+0x54/0x16c
   udp_queue_rcv_skb+0x78/0x144
   udp_unicast_rcv_skb+0x8c/0xa4
   __udp4_lib_rcv+0x490/0x68c
   udp_rcv+0x20/0x30
   ip_protocol_deliver_rcu+0x1b0/0x33c
   ip_local_deliver+0xd8/0x1f0
   ip_rcv+0x98/0x1a4
   deliver_ptype_list_skb+0x98/0x1ec
   __netif_receive_skb_core+0x978/0xc60

Fix this by marking these skbs as GSO_DODGY so segmentation can handle
the tail updates accordingly.
Comment 1 Keith Grant 2025-09-17 17:48:17 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091716-CVE-2022-50365-9a71@gregkh/T