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

tcp: fix potential race in tcp_v6_syn_recv_sock()

Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.

After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.

Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.

Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.

This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.

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Wed, 06 May 2026 12:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tcp: fix potential race in tcp_v6_syn_recv_sock() Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context.
Title tcp: fix potential race in tcp_v6_syn_recv_sock()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-06T11:28:05.569Z

Reserved: 2026-05-01T14:12:55.992Z

Link: CVE-2026-43198

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-06T12:16:38.857

Modified: 2026-05-06T13:07:51.607

Link: CVE-2026-43198

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

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