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  1. 06 10月, 2010 1 次提交
  2. 08 9月, 2010 1 次提交
    • T
      UNIX: Do not loop forever at unix_autobind(). · 8df73ff9
      Tetsuo Handa 提交于
      We assumed that unix_autobind() never fails if kzalloc() succeeded.
      But unix_autobind() allows only 1048576 names. If /proc/sys/fs/file-max is
      larger than 1048576 (e.g. systems with more than 10GB of RAM), a local user can
      consume all names using fork()/socket()/bind().
      
      If all names are in use, those who call bind() with addr_len == sizeof(short)
      or connect()/sendmsg() with setsockopt(SO_PASSCRED) will continue
      
        while (1)
              yield();
      
      loop at unix_autobind() till a name becomes available.
      This patch adds a loop counter in order to give up after 1048576 attempts.
      
      Calling yield() for once per 256 attempts may not be sufficient when many names
      are already in use, for __unix_find_socket_byname() can take long time under
      such circumstance. Therefore, this patch also adds cond_resched() call.
      
      Note that currently a local user can consume 2GB of kernel memory if the user
      is allowed to create and autobind 1048576 UNIX domain sockets. We should
      consider adding some restriction for autobind operation.
      Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8df73ff9
  3. 07 9月, 2010 1 次提交
  4. 21 7月, 2010 1 次提交
    • N
      drop_monitor: convert some kfree_skb call sites to consume_skb · 70d4bf6d
      Neil Horman 提交于
      Convert a few calls from kfree_skb to consume_skb
      
      Noticed while I was working on dropwatch that I was detecting lots of internal
      skb drops in several places.  While some are legitimate, several were not,
      freeing skbs that were at the end of their life, rather than being discarded due
      to an error.  This patch converts those calls sites from using kfree_skb to
      consume_skb, which quiets the in-kernel drop_monitor code from detecting them as
      drops.  Tested successfully by myself
      Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      70d4bf6d
  5. 17 6月, 2010 3 次提交
  6. 04 5月, 2010 1 次提交
  7. 02 5月, 2010 1 次提交
    • E
      net: sock_def_readable() and friends RCU conversion · 43815482
      Eric Dumazet 提交于
      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: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      43815482
  8. 21 4月, 2010 1 次提交
  9. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  10. 19 2月, 2010 1 次提交
  11. 18 1月, 2010 1 次提交
  12. 30 11月, 2009 1 次提交
  13. 12 11月, 2009 1 次提交
    • E
      sysctl net: Remove unused binary sysctl code · f8572d8f
      Eric W. Biederman 提交于
      Now that sys_sysctl is a compatiblity wrapper around /proc/sys
      all sysctl strategy routines, and all ctl_name and strategy
      entries in the sysctl tables are unused, and can be
      revmoed.
      
      In addition neigh_sysctl_register has been modified to no longer
      take a strategy argument and it's callers have been modified not
      to pass one.
      
      Cc: "David Miller" <davem@davemloft.net>
      Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
      Cc: netdev@vger.kernel.org
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      f8572d8f
  14. 11 11月, 2009 1 次提交
  15. 06 11月, 2009 1 次提交
  16. 19 10月, 2009 1 次提交
    • T
      AF_UNIX: Fix deadlock on connecting to shutdown socket · 77238f2b
      Tomoki Sekiyama 提交于
      I found a deadlock bug in UNIX domain socket, which makes able to DoS
      attack against the local machine by non-root users.
      
      How to reproduce:
      1. Make a listening AF_UNIX/SOCK_STREAM socket with an abstruct
          namespace(*), and shutdown(2) it.
       2. Repeat connect(2)ing to the listening socket from the other sockets
          until the connection backlog is full-filled.
       3. connect(2) takes the CPU forever. If every core is taken, the
          system hangs.
      
      PoC code: (Run as many times as cores on SMP machines.)
      
      int main(void)
      {
      	int ret;
      	int csd;
      	int lsd;
      	struct sockaddr_un sun;
      
      	/* make an abstruct name address (*) */
      	memset(&sun, 0, sizeof(sun));
      	sun.sun_family = PF_UNIX;
      	sprintf(&sun.sun_path[1], "%d", getpid());
      
      	/* create the listening socket and shutdown */
      	lsd = socket(AF_UNIX, SOCK_STREAM, 0);
      	bind(lsd, (struct sockaddr *)&sun, sizeof(sun));
      	listen(lsd, 1);
      	shutdown(lsd, SHUT_RDWR);
      
      	/* connect loop */
      	alarm(15); /* forcely exit the loop after 15 sec */
      	for (;;) {
      		csd = socket(AF_UNIX, SOCK_STREAM, 0);
      		ret = connect(csd, (struct sockaddr *)&sun, sizeof(sun));
      		if (-1 == ret) {
      			perror("connect()");
      			break;
      		}
      		puts("Connection OK");
      	}
      	return 0;
      }
      
      (*) Make sun_path[0] = 0 to use the abstruct namespace.
          If a file-based socket is used, the system doesn't deadlock because
          of context switches in the file system layer.
      
      Why this happens:
       Error checks between unix_socket_connect() and unix_wait_for_peer() are
       inconsistent. The former calls the latter to wait until the backlog is
       processed. Despite the latter returns without doing anything when the
       socket is shutdown, the former doesn't check the shutdown state and
       just retries calling the latter forever.
      
      Patch:
       The patch below adds shutdown check into unix_socket_connect(), so
       connect(2) to the shutdown socket will return -ECONREFUSED.
      Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
      Signed-off-by: NMasanori Yoshida <masanori.yoshida.tv@hitachi.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      77238f2b
  17. 07 10月, 2009 1 次提交
  18. 12 9月, 2009 1 次提交
    • M
      net: unix: fix sending fds in multiple buffers · 8ba69ba6
      Miklos Szeredi 提交于
      Kalle Olavi Niemitalo reported that:
      
        "..., when one process calls sendmsg once to send 43804 bytes of
        data and one file descriptor, and another process then calls recvmsg
        three times to receive the 16032+16032+11740 bytes, each of those
        recvmsg calls returns the file descriptor in the ancillary data.  I
        confirmed this with strace.  The behaviour differs from Linux
        2.6.26, where reportedly only one of those recvmsg calls (I think
        the first one) returned the file descriptor."
      
      This bug was introduced by a patch from me titled "net: unix: fix inflight
      counting bug in garbage collector", commit 6209344f.
      
      And the reason is, quoting Kalle:
      
        "Before your patch, unix_attach_fds() would set scm->fp = NULL, so
        that if the loop in unix_stream_sendmsg() ran multiple iterations,
        it could not call unix_attach_fds() again.  But now,
        unix_attach_fds() leaves scm->fp unchanged, and I think this causes
        it to be called multiple times and duplicate the same file
        descriptors to each struct sk_buff."
      
      Fix this by introducing a flag that is cleared at the start and set
      when the fds attached to the first buffer.  The resulting code should
      work equivalently to the one on 2.6.26.
      Reported-by: NKalle Olavi Niemitalo <kon@iki.fi>
      Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8ba69ba6
  19. 10 7月, 2009 1 次提交
    • J
      net: adding memory barrier to the poll and receive callbacks · a57de0b4
      Jiri Olsa 提交于
      Adding memory barrier after the poll_wait function, paired with
      receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
      to wrap the memory barrier.
      
      Without the memory barrier, following race can happen.
      The race fires, when following code paths meet, and the tp->rcv_nxt
      and __add_wait_queue updates stay in CPU caches.
      
      CPU1                         CPU2
      
      sys_select                   receive packet
        ...                        ...
        __add_wait_queue           update tp->rcv_nxt
        ...                        ...
        tp->rcv_nxt check          sock_def_readable
        ...                        {
        schedule                      ...
                                      if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                                              wake_up_interruptible(sk->sk_sleep)
                                      ...
                                   }
      
      If there was no cache the code would work ok, since the wait_queue and
      rcv_nxt are opposit to each other.
      
      Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
      passed the tp->rcv_nxt check and sleeps, or will get the new value for
      tp->rcv_nxt and will return with new data mask.
      In both cases the process (CPU1) is being added to the wait queue, so the
      waitqueue_active (CPU2) call cannot miss and will wake up CPU1.
      
      The bad case is when the __add_wait_queue changes done by CPU1 stay in its
      cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1 will then
      endup calling schedule and sleep forever if there are no more data on the
      socket.
      
      Calls to poll_wait in following modules were ommited:
      	net/bluetooth/af_bluetooth.c
      	net/irda/af_irda.c
      	net/irda/irnet/irnet_ppp.c
      	net/mac80211/rc80211_pid_debugfs.c
      	net/phonet/socket.c
      	net/rds/af_rds.c
      	net/rfkill/core.c
      	net/sunrpc/cache.c
      	net/sunrpc/rpc_pipe.c
      	net/tipc/socket.c
      Signed-off-by: NJiri Olsa <jolsa@redhat.com>
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a57de0b4
  20. 18 6月, 2009 1 次提交
  21. 01 4月, 2009 1 次提交
  22. 27 2月, 2009 1 次提交
  23. 01 1月, 2009 1 次提交
  24. 27 11月, 2008 1 次提交
  25. 26 11月, 2008 1 次提交
  26. 24 11月, 2008 2 次提交
  27. 20 11月, 2008 2 次提交
  28. 17 11月, 2008 3 次提交
  29. 14 11月, 2008 1 次提交
  30. 10 11月, 2008 1 次提交
    • M
      net: unix: fix inflight counting bug in garbage collector · 6209344f
      Miklos Szeredi 提交于
      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: NAndrea Bittau <a.bittau@cs.ucl.ac.uk>
      Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
      CC: stable@kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6209344f
  31. 04 11月, 2008 1 次提交
    • A
      net: '&' redux · 6d9f239a
      Alexey Dobriyan 提交于
      I want to compile out proc_* and sysctl_* handlers totally and
      stub them to NULL depending on config options, however usage of &
      will prevent this, since taking adress of NULL pointer will break
      compilation.
      
      So, drop & in front of every ->proc_handler and every ->strategy
      handler, it was never needed in fact.
      Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6d9f239a
  32. 02 11月, 2008 2 次提交
  33. 23 10月, 2008 1 次提交