On Tue, Apr 21, 2020 at 07:08:33PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 99e3a236dd43d06c65af0a2ef9cb44306aef6e02 Mon Sep 17 00:00:00 2001
From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
Date: Tue, 14 Apr 2020 09:35:15 +0200
Subject: [PATCH] xsk: Add missing check on user supplied headroom size
Add a check that the headroom cannot be larger than the available
space in the chunk. In the current code, a malicious user can set the
headroom to a value larger than the chunk size minus the fixed XDP
headroom. That way packets with a length larger than the supported
size in the umem could get accepted and result in an out-of-bounds
write.
Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt")
Reported-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx>
Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207225
Link: https://lore.kernel.org/bpf/1586849715-23490-1-git-send-email-magnus.karlsson@xxxxxxxxx
Conflict with 624676e78899 ("xdp: xdp_umem: replace kmap on vmap for
umem map") around 'i' going away. Fixed and queued for 4.19.
--
Thanks,
Sasha
