kernel/include/net/af_unix.h, branch linux-3.0.y

net: Remove KERNEL cpp checks from include/net

2011-04-24T17:54:56Z

These header files are never installed to user consumption, so any __KERNEL__ cpp checks are superfluous. Projects should also not copy these files into their userland utility sources and try to use them there. If they insist on doing so, the onus is on them to sanitize the headers as needed. Signed-off-by: David S. Miller

af_unix: limit recursion level

2010-11-29T17:45:15Z

Its easy to eat all kernel memory and trigger NMI watchdog, using an exploit program that queues unix sockets on top of others. lkml ref : http://lkml.org/lkml/2010/11/25/8 This mechanism is used in applications, one choice we have is to have a recursion limit. Other limits might be needed as well (if we queue other types of files), since the passfd mechanism is currently limited by socket receive queue sizes only. Add a recursion_level to unix socket, allowing up to 4 levels. Each time we send an unix socket through sendfd mechanism, we copy its recursion level (plus one) to receiver. This recursion level is cleared when socket receive queue is emptied. Reported-by: Марк Коренберг Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

af_unix: Allow credentials to work across user and pid namespaces.

2010-06-16T21:58:16Z

In unix_skb_parms store pointers to struct pid and struct cred instead of raw uid, gid, and pid values, then translate the credentials on reception into values that are meaningful in the receiving processes namespaces. Signed-off-by: Eric W. Biederman Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller

net: sock_def_readable() and friends RCU conversion

2010-05-01T22:00:15Z

sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Fix soft lockups/OOM issues w/ unix garbage collector

2008-11-26T23:32:27Z

This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier Signed-off-by: David S. Miller

net: unix: fix inflight counting bug in garbage collector

2008-11-09T19:17:33Z

Previously I assumed that the receive queues of candidates don't change during the GC. This is only half true, nothing can be received from the queues (see comment in unix_gc()), but buffers could be added through the other half of the socket pair, which may still have file descriptors referring to it. This can result in inc_inflight_move_tail() erronously increasing the "inflight" counter for a unix socket for which dec_inflight() wasn't previously called. This in turn can trigger the "BUG_ON(total_refs < inflight_refs)" in a later garbage collection run. Fix this by only manipulating the "inflight" counter for sockets which are candidates themselves. Duplicating the file references in unix_attach_fds() is also needed to prevent a socket becoming a candidate for GC while the skb that contains it is not yet queued. Reported-by: Andrea Bittau Signed-off-by: Miklos Szeredi CC: stable@kernel.org Signed-off-by: Linus Torvalds

[PATCH] f_count may wrap around

2008-07-27T00:53:40Z

make it atomic_long_t; while we are at it, get rid of useless checks in affs, hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0. Signed-off-by: Al Viro

[AF_UNIX]: Remove unused declaration of sysctl_unix_max_dgram_qlen.

2008-01-28T22:57:13Z

Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[UNIX]: Extend unix_sysctl_(un)register prototypes

2008-01-28T22:55:21Z

Add the struct net * argument to both of them to use in the future. Also make the register one return an error code. It is useless right now, but will make the future patches much simpler. Signed-off-by: Pavel Emelyanov Acked-by: Eric W. Biederman Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

[AF_UNIX]: Make unix_tot_inflight counter non-atomic

2007-11-11T06:06:01Z

This counter is _always_ modified under the unix_gc_lock spinlock, so its atomicity can be provided w/o additional efforts. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller