[PATCH] arp: fix seq_file handling bug

[Arnaldo Carvalho de Melo <acme@conectiva.com.br>]

Hi David,

	Please pull from:

bk://kernel.bkbits.net/acme/net-2.5

	Now there is just this outstanding changeset. Now I have
some time to devote to fixing /proc/net/tcp seq_file handling.

- Arnaldo

You can import this changeset into BK by piping this whole message to:
'| bk receive [path to repository]' or apply the patch as usual.

===================================================================


ChangeSet@1.864, 2002-11-30 13:30:49-02:00, acme@conectiva.com.br
  o arp: fix seq_file handling bug
  
  When midnigth commander viewer is invoked it first opens the file, read
  4 bytes (probably looking for a magic number), reading only 4 bytes makes
  state->is_pneigh not to be set neither the lock is taken, because only
  the header is being produced (v = (void *)1), so when arp_seq_stop is 
  called the lock is dropped without having being taken: b00m
  
  Thanks to Serge Kuznetsov for reporting this to me. Other seq_file
  code may have this problem, but by using mc viewer in all of /proc/net
  I haven't been able to reproduce this problem with any other file.


 arp.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)


diff -Nru a/net/ipv4/arp.c b/net/ipv4/arp.c
--- a/net/ipv4/arp.c	Sat Nov 30 13:31:52 2002
+++ b/net/ipv4/arp.c	Sat Nov 30 13:31:52 2002
@@ -1282,7 +1282,7 @@
 {
 	struct arp_iter_state* state = seq->private;
 
-	if (!state->is_pneigh)
+	if (!state->is_pneigh && v != (void *)1)
 		read_unlock_bh(&arp_tbl.lock);
 }
 

===================================================================


This BitKeeper patch contains the following changesets:
1.864
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