linux-stable.git/net/sunrpc/cache.c, branch linux-3.18.y

sunrpc: don't mark uninitialised items as VALID.

2019-05-16T07:17:13+00:00

commit d58431eacb226222430940134d97bfd72f292fcd upstream.

A recent commit added a call to cache_fresh_locked()
when an expired item was found.
The call sets the CACHE_VALID flag, so it is important
that the item actually is valid.
There are two ways it could be valid:
1/ If ->update has been called to fill in relevant content
2/ if CACHE_NEGATIVE is set, to say that content doesn't exist.

An expired item that is waiting for an update will be neither.
Setting CACHE_VALID will mean that a subsequent call to cache_put()
will be likely to dereference uninitialised pointers.

So we must make sure the item is valid, and we already have code to do
that in try_to_negate_entry().  This takes the hash lock and so cannot
be used directly, so take out the two lines that we need and use them.

Now cache_fresh_locked() is certain to be called only on
a valid item.

Cc: stable@kernel.org # 2.6.35
Fixes: 4ecd55ea0742 ("sunrpc: fix cache_head leak due to queued request")
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

sunrpc: fix cache_head leak due to queued request

2019-01-13T09:07:11+00:00

commit 4ecd55ea074217473f94cfee21bb72864d39f8d7 upstream.

After commit d202cce8963d, an expired cache_head can be removed from the
cache_detail's hash.

However, the expired cache_head may be waiting for a reply from a
previously submitted request. Such a cache_head has an increased
refcounter and therefore it won't be freed after cache_put(freeme).

Because the cache_head was removed from the hash it cannot be found
during cache_clean() and can be leaked forever, together with stalled
cache_request and other taken resources.

In our case we noticed it because an entry in the export cache was
holding a reference on a filesystem.

Fixes d202cce8963d ("sunrpc: never return expired entries in sunrpc_cache_lookup")
Cc: Pavel Tikhomirov 
Cc: stable@kernel.org # 2.6.35
Signed-off-by: Vasily Averin 
Reviewed-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race

2016-07-12T12:47:59+00:00

[ Upstream commit a6ab1e8126d205238defbb55d23661a3a5c6a0d8 ]

sunrpc_cache_pipe_upcall() can detect a race if CACHE_PENDING is no longer
set.  In this case it aborts the queuing of the upcall.
However it has already taken a new counted reference on "h" and
doesn't "put" it, even though it frees the data structure holding the reference.

So let's delay the "cache_get" until we know we need it.

Fixes: f9e1aedc6c79 ("sunrpc/cache: remove races with queuing an upcall.")
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

sunrpc/cache: fix off-by-one in qword_get()

2016-03-08T06:14:06+00:00

[ Upstream commit b7052cd7bcf3c1478796e93e3dff2b44c9e82943 ]

The qword_get() function NUL-terminates its output buffer.  If the input
string is in hex format \xXXXX... and the same length as the output
buffer, there is an off-by-one:

  int qword_get(char **bpp, char *dest, int bufsize)
  {
      ...
      while (len < bufsize) {
          ...
          *dest++ = (h << 4) | l;
          len++;
      }
      ...
      *dest = '\0';
      return len;
  }

This patch ensures the NUL terminator doesn't fall outside the output
buffer.

Signed-off-by: Stefan Hajnoczi 
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

sunrpc: fix braino in ->poll()

2015-03-14T19:37:27+00:00

commit 1711fd9addf214823b993468567cab1f8254fc51 upstream.

POLL_OUT isn't what callers of ->poll() are expecting to see; it's
actually __SI_POLL | 2 and it's a siginfo code, not a poll bitmap
bit...

Signed-off-by: Al Viro 
Cc: Bruce Fields 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

SUNRPC: Fix printk that is not only for nfsd

2014-05-08T18:59:51+00:00

Signed-off-by: Kinglong Mee 
Signed-off-by: J. Bruce Fields

Merge branch 'for-3.14' of git://linux-nfs.org/~bfields/linux

2014-01-30T18:18:43+00:00

Pull nfsd updates from Bruce Fields:
 - Handle some loose ends from the vfs read delegation support.
   (For example nfsd can stop breaking leases on its own in a
    fewer places where it can now depend on the vfs to.)
 - Make life a little easier for NFSv4-only configurations
   (thanks to Kinglong Mee).
 - Fix some gss-proxy problems (thanks Jeff Layton).
 - miscellaneous bug fixes and cleanup

* 'for-3.14' of git://linux-nfs.org/~bfields/linux: (38 commits)
  nfsd: consider CLAIM_FH when handing out delegation
  nfsd4: fix delegation-unlink/rename race
  nfsd4: delay setting current_fh in open
  nfsd4: minor nfs4_setlease cleanup
  gss_krb5: use lcm from kernel lib
  nfsd4: decrease nfsd4_encode_fattr stack usage
  nfsd: fix encode_entryplus_baggage stack usage
  nfsd4: simplify xdr encoding of nfsv4 names
  nfsd4: encode_rdattr_error cleanup
  nfsd4: nfsd4_encode_fattr cleanup
  minor svcauth_gss.c cleanup
  nfsd4: better VERIFY comment
  nfsd4: break only delegations when appropriate
  NFSD: Fix a memory leak in nfsd4_create_session
  sunrpc: get rid of use_gssp_lock
  sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt
  sunrpc: don't wait for write before allowing reads from use-gss-proxy file
  nfsd: get rid of unused function definition
  Define op_iattr for nfsd4_open instead using macro
  NFSD: fix compile warning without CONFIG_NFSD_V3
  ...

net: replace macros net_random and net_srandom with direct calls to prandom

2014-01-14T23:15:25+00:00

This patch removes the net_random and net_srandom macros and replaces
them with direct calls to the prandom ones. As new commits only seem to
use prandom_u32 there is no use to keep them around.
This change makes it easier to grep for users of prandom_u32.

Signed-off-by: Aruna-Hewapathirane 
Suggested-by: Hannes Frederic Sowa 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

net/sunrpc/cache: simplify code by using hex_pack_byte()

2013-12-12T16:37:17+00:00

hex_pack_byte() is a fast way to convert a byte in its ASCII representation. We
may use it instead of custom approach.

Signed-off-by: Andy Shevchenko 
Signed-off-by: J. Bruce Fields

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-07-14T18:42:26+00:00

Pull more vfs stuff from Al Viro:
 "O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including
  making simple_lookup() usable for filesystems with non-NULL s_d_op,
  which allows us to get rid of quite a bit of ugliness"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sunrpc: now we can just set ->s_d_op
  cgroup: we can use simple_lookup() now
  efivarfs: we can use simple_lookup() now
  make simple_lookup() usable for filesystems that set ->s_d_op
  configfs: don't open-code d_alloc_name()
  __rpc_lookup_create_exclusive: pass string instead of qstr
  rpc_create_*_dir: don't bother with qstr
  llist: llist_add() can use llist_add_batch()
  llist: fix/simplify llist_add() and llist_add_batch()
  fput: turn "list_head delayed_fput_list" into llist_head
  fs/file_table.c:fput(): add comment
  Safer ABI for O_TMPFILE