linux/net/unix
Miklos Szeredi cbcf01128d af_unix: fix garbage collect vs MSG_PEEK
unix_gc() assumes that candidate sockets can never gain an external
reference (i.e.  be installed into an fd) while the unix_gc_lock is
held.  Except for MSG_PEEK this is guaranteed by modifying inflight
count under the unix_gc_lock.

MSG_PEEK does not touch any variable protected by unix_gc_lock (file
count is not), yet it needs to be serialized with garbage collection.
Do this by locking/unlocking unix_gc_lock:

 1) increment file count

 2) lock/unlock barrier to make sure incremented file count is visible
    to garbage collection

 3) install file into fd

This is a lock barrier (unlike smp_mb()) that ensures that garbage
collection is run completely before or completely after the barrier.

Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-28 10:18:00 -07:00
..
af_unix.c af_unix: fix garbage collect vs MSG_PEEK 2021-07-28 10:18:00 -07:00
diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
garbage.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 62 2019-05-24 17:36:46 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile net: split out functions related to registering inflight socket files 2019-02-28 08:24:23 -07:00
scm.c io_uring: move io_uring_get_socket() into io_uring.h 2020-09-30 20:32:33 -06:00
scm.h net: split out functions related to registering inflight socket files 2019-02-28 08:24:23 -07:00
sysctl_net_unix.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00