6ef652f35d
[ Upstream commit 458e279f861d3f61796894cd158b780765a1569f ]
Currently, if you bind the socket to something like:
servaddr.sin6_family = AF_INET6;
servaddr.sin6_port = htons(0);
servaddr.sin6_scope_id = 0;
inet_pton(AF_INET6, "::1", &servaddr.sin6_addr);
And then request a connect to:
connaddr.sin6_family = AF_INET6;
connaddr.sin6_port = htons(20000);
connaddr.sin6_scope_id = if_nametoindex("lo");
inet_pton(AF_INET6, "fe88::1", &connaddr.sin6_addr);
What the stack does is:
- bind the socket
- create a new asoc
- to handle the connect
- copy the addresses that can be used for the given scope
- try to connect
But the copy returns 0 addresses, and the effect is that it ends up
trying to connect as if the socket wasn't bound, which is not the
desired behavior. This unexpected behavior also allows KASLR leaks
through SCTP diag interface.
The fix here then is, if when trying to copy the addresses that can
be used for the scope used in connect() it returns 0 addresses, bail
out. This is what TCP does with a similar reproducer.
Reported-by: Pietro Borrello <borrello@diag.uniroma1.it>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/9fcd182f1099f86c6661f3717f63712ddd1c676c.1674496737.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.