Skip to content

K
kernel_linux

OpenHarmony / kernel_linux
上一次同步 4 年多

通知 15
Star 8
Fork 2
K
kernel_linux
切换分支/标签
  1. 01 4月, 2014 1 次提交
    • S
      nfsd: check passed socket's net matches NFSd superblock's one · 30646394
      由 Stanislav Kinsbursky 提交于 
      There could be a case, when NFSd file system is mounted in network, different
to socket's one, like below:

"ip netns exec" creates new network and mount namespace, which duplicates NFSd
mount point, created in init_net context. And thus NFS server stop in nested
network context leads to RPCBIND client destruction in init_net.
Then, on NFSd start in nested network context, rpc.nfsd process creates socket
in nested net and passes it into "write_ports", which leads to RPCBIND sockets
creation in init_net context because of the same reason (NFSd monut point was
created in init_net context). An attempt to register passed socket in nested
net leads to panic, because no RPCBIND client present in nexted network
namespace.

This patch add check that passed socket's net matches NFSd superblock's one.
And returns -EINVAL error to user psace otherwise.

v2: Put socket on exit.
Reported-by: NWeng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      30646394
  3. 10 4月, 2013 1 次提交
  5. 04 4月, 2013 1 次提交
  7. 03 4月, 2013 1 次提交
  9. 04 3月, 2013 1 次提交
    • E
      fs: Limit sys_mount to only request filesystem modules. · 7f78e035
      由 Eric W. Biederman 提交于 
      Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: NKees Cook <keescook@chromium.org>
Reported-by: NKees Cook <keescook@google.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      7f78e035
  11. 23 2月, 2013 1 次提交
  13. 16 2月, 2013 2 次提交
  15. 05 2月, 2013 1 次提交
  17. 24 1月, 2013 1 次提交
  19. 11 12月, 2012 5 次提交
  21. 29 11月, 2012 1 次提交
  23. 28 11月, 2012 3 次提交
  25. 10 9月, 2012 1 次提交
    • J
      nfsd: remove unused listener-removal interfaces · eccf50c1
      由 J. Bruce Fields 提交于 
      You can use nfsd/portlist to give nfsd additional sockets to listen on.
In theory you can also remove listening sockets this way.  But nobody's
ever done that as far as I can tell.

Also this was partially broken in 2.6.25, by
a217813f "knfsd: Support adding
transports by writing portlist file".

(Note that we decide whether to take the "delfd" case by checking for a
digit--but what's actually expected in that case is something made by
svc_one_sock_name(), which won't begin with a digit.)

So, let's just rip out this stuff.
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      eccf50c1
  27. 22 8月, 2012 2 次提交
  29. 21 8月, 2012 1 次提交
  31. 25 7月, 2012 1 次提交
  33. 01 6月, 2012 1 次提交
  35. 12 4月, 2012 7 次提交
  37. 29 3月, 2012 1 次提交
  39. 26 3月, 2012 2 次提交
  41. 01 2月, 2012 2 次提交
  43. 07 1月, 2012 1 次提交
  45. 08 11月, 2011 2 次提交