This is a note to let you know that I've just added the patch titled ipv6: raw: check passed optlen before reading to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-raw-check-passed-optlen-before-reading.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0864470146d042f6bbe86cb011ace92f895e0628 Author: Tamir Duberstein <tamird@xxxxxxxxx> Date: Wed Dec 29 15:09:47 2021 -0500 ipv6: raw: check passed optlen before reading [ Upstream commit fb7bc9204095090731430c8921f9e629740c110a ] Add a check that the user-provided option is at least as long as the number of bytes we intend to read. Before this patch we would blindly read sizeof(int) bytes even in cases where the user passed optlen<sizeof(int), which would potentially read garbage or fault. Discovered by new tests in https://github.com/google/gvisor/pull/6957 . The original get_user call predates history in the git repo. Signed-off-by: Tamir Duberstein <tamird@xxxxxxxxx> Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211229200947.2862255-1-willemdebruijn.kernel@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 00f133a55ef7c..38349054e361e 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1020,6 +1020,9 @@ static int do_rawv6_setsockopt(struct sock *sk, int level, int optname, struct raw6_sock *rp = raw6_sk(sk); int val; + if (optlen < sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) return -EFAULT;