51bae889fe
Commitcf2f225e26("af_unix: Put a socket into a per-netns hash table.") accidentally broke user API for pathname sockets. A socket was able to connect() to a pathname socket whose file was visible even if they were in different network namespaces. The commit puts all sockets into a per-netns hash table. As a result, connect() to a pathname socket in a different netns fails to find it in the caller's per-netns hash table and returns -ECONNREFUSED even when the task can view the peer socket file. We can reproduce this issue by: Console A: # python3 >>> from socket import * >>> s = socket(AF_UNIX, SOCK_STREAM, 0) >>> s.bind('test') >>> s.listen(32) Console B: # ip netns add test # ip netns exec test sh # python3 >>> from socket import * >>> s = socket(AF_UNIX, SOCK_STREAM, 0) >>> s.connect('test') Note when dumping sockets by sock_diag, procfs, and bpf_iter, they are filtered only by netns. In other words, even if they are visible and connect()able, all sockets in different netns are skipped while iterating sockets. Thus, we need a fix only for finding a peer pathname socket. This patch adds a global hash table for pathname sockets, links them with sk_bind_node, and uses it in unix_find_socket_byinode(). By doing so, we can keep sockets in per-netns hash tables and dump them easily. Thanks to Sachin Sant and Leonard Crestez for reports, logs and a reproducer. Fixes:cf2f225e26("af_unix: Put a socket into a per-netns hash table.") Reported-by: Sachin Sant <sachinp@linux.ibm.com> Reported-by: Leonard Crestez <cdleonard@gmail.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Tested-by: Leonard Crestez <cdleonard@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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.