Subject: CVE-2024-35890: gro: fix ownership transfer

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

gro: fix ownership transfer

If packets are GROed with fraglist they might be segmented later on and
continue their journey in the stack. In skb_segment_list those skbs can
be reused as-is. This is an issue as their destructor was removed in
skb_gro_receive_list but not the reference to their socket, and then
they can't be orphaned. Fix this by also removing the reference to the
socket.

For example this could be observed,

  kernel BUG at include/linux/skbuff.h:3131!  (skb_orphan)
  RIP: 0010:ip6_rcv_core+0x11bc/0x19a0
  Call Trace:
   ipv6_list_rcv+0x250/0x3f0
   __netif_receive_skb_list_core+0x49d/0x8f0
   netif_receive_skb_list_internal+0x634/0xd40
   napi_complete_done+0x1d2/0x7d0
   gro_cell_poll+0x118/0x1f0

A similar construction is found in skb_gro_receive, apply the same
change there.

The Linux kernel CVE team has assigned CVE-2024-35890 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 5.15 with commit 5e10da5385d2 and fixed in 5.15.154 with commit d225b0ac96dc
	Issue introduced in 5.15 with commit 5e10da5385d2 and fixed in 6.1.85 with commit 2eeab8c47c3c
	Issue introduced in 5.15 with commit 5e10da5385d2 and fixed in 6.6.26 with commit fc126c1d51e9
	Issue introduced in 5.15 with commit 5e10da5385d2 and fixed in 6.8.5 with commit 5b3b67f73129
	Issue introduced in 5.15 with commit 5e10da5385d2 and fixed in 6.9 with commit ed4cccef64c1

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-35890
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	net/core/gro.c
	net/ipv4/udp_offload.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d225b0ac96dc40d7e8ae2bc227eb2c56e130975f
	https://git.kernel.org/stable/c/2eeab8c47c3c0276e0746bc382f405c9a236a5ad
	https://git.kernel.org/stable/c/fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6
	https://git.kernel.org/stable/c/5b3b67f731296027cceb3efad881ae281213f86f
	https://git.kernel.org/stable/c/ed4cccef64c1d0d5b91e69f7a8a6697c3a865486