tree 2397245bba143fbb9e4147f627dcfc8faefbd7d2
parent 77dd8477b7c52179bd0ccbbe009bd28c1ffd9149
author Eric Dumazet <edumazet@google.com> 1693887818 +0000
committer Oleksandr Tymoshenko <ovt@google.com> 1697834560 +0000

igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU

commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream.

This is a follow up of commit 915d975b2ffa ("net: deal with integer
overflows in kmalloc_reserve()") based on David Laight feedback.

Back in 2010, I failed to realize malicious users could set dev->mtu
to arbitrary values. This mtu has been since limited to 0x7fffffff but
regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack()
to allocate more than IP_MAX_MTU and risk various skb fields overflows.

BUG=b/306357801
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2023-42752 in the Linux kernel.

cos-patch: security-moderate
Fixes: 57e1ab6eaddc ("igmp: refine skb allocations")
Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Cc: Kyle Zeng <zengyhkyle@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I04ca8641dfe0d61b103a8ef941196ec9c837fb79
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/59734
Reviewed-by: Arnav Kansal <rnv@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>