tree e70d1ce001468e63ce0fe7444bb1010fade08944
parent 61b4d8b623444b80bdd2ee7318495a0ca7d705d6
author Vaibhav Rustagi <vaibhavrustagi@google.com> 1647972286 -0700
committer COS Cherry Picker <cloud-image-release@prod.google.com> 1648012087 -0700

esp: Fix possible buffer overflow in ESP transformation

[ Upstream commit ebe48d368e97d007bfeb76fcb065d6cfc4c96645 ]

The maximum message size that can be send is bigger than
the  maximum site that skb_page_frag_refill can allocate.
So it is possible to write beyond the allocated buffer.

Fix this by doing a fallback to COW in that case.

v2:

Avoid get get_order() costs as suggested by Linus Torvalds.

For having the patch build on v5.4, following changes are done:
 - `SKB_FRAG_PAGE_ORDER` declaration is moved from net/core/sock.c to include/net/sock.c.
 - Remove changes introduced due to `xfrm: add support for UDPv6 encapsulation of ESP` in esp6_output_head

BUG=b/225430860
TEST=presubmit
RELEASE_NOTE=Fixed possible buffer overflow in ESP transformation.

cos-patch: bug
Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Reported-by: valis <sec@valis.email>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Change-Id: Ibba7d1063e1e78fe8cecb2d0ae1e94a586101a93
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/31081
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>