1. 15 12月, 2012 1 次提交
    • E
      userns: Require CAP_SYS_ADMIN for most uses of setns. · 5e4a0847
      Eric W. Biederman 提交于
      Andy Lutomirski <luto@amacapital.net> found a nasty little bug in
      the permissions of setns.  With unprivileged user namespaces it
      became possible to create new namespaces without privilege.
      
      However the setns calls were relaxed to only require CAP_SYS_ADMIN in
      the user nameapce of the targed namespace.
      
      Which made the following nasty sequence possible.
      
      pid = clone(CLONE_NEWUSER | CLONE_NEWNS);
      if (pid == 0) { /* child */
      	system("mount --bind /home/me/passwd /etc/passwd");
      }
      else if (pid != 0) { /* parent */
      	char path[PATH_MAX];
      	snprintf(path, sizeof(path), "/proc/%u/ns/mnt");
      	fd = open(path, O_RDONLY);
      	setns(fd, 0);
      	system("su -");
      }
      
      Prevent this possibility by requiring CAP_SYS_ADMIN
      in the current user namespace when joing all but the user namespace.
      Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      5e4a0847
  2. 20 11月, 2012 1 次提交
    • E
      proc: Usable inode numbers for the namespace file descriptors. · 98f842e6
      Eric W. Biederman 提交于
      Assign a unique proc inode to each namespace, and use that
      inode number to ensure we only allocate at most one proc
      inode for every namespace in proc.
      
      A single proc inode per namespace allows userspace to test
      to see if two processes are in the same namespace.
      
      This has been a long requested feature and only blocked because
      a naive implementation would put the id in a global space and
      would ultimately require having a namespace for the names of
      namespaces, making migration and certain virtualization tricks
      impossible.
      
      We still don't have per superblock inode numbers for proc, which
      appears necessary for application unaware checkpoint/restart and
      migrations (if the application is using namespace file descriptors)
      but that is now allowd by the design if it becomes important.
      
      I have preallocated the ipc and uts initial proc inode numbers so
      their structures can be statically initialized.
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      98f842e6
  3. 19 11月, 2012 5 次提交
  4. 13 10月, 2012 1 次提交
    • J
      vfs: define struct filename and have getname() return it · 91a27b2a
      Jeff Layton 提交于
      getname() is intended to copy pathname strings from userspace into a
      kernel buffer. The result is just a string in kernel space. It would
      however be quite helpful to be able to attach some ancillary info to
      the string.
      
      For instance, we could attach some audit-related info to reduce the
      amount of audit-related processing needed. When auditing is enabled,
      we could also call getname() on the string more than once and not
      need to recopy it from userspace.
      
      This patchset converts the getname()/putname() interfaces to return
      a struct instead of a string. For now, the struct just tracks the
      string in kernel space and the original userland pointer for it.
      
      Later, we'll add other information to the struct as it becomes
      convenient.
      Signed-off-by: NJeff Layton <jlayton@redhat.com>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      91a27b2a
  5. 12 10月, 2012 1 次提交
  6. 23 9月, 2012 1 次提交
    • A
      do_add_mount()/umount -l races · 156cacb1
      Al Viro 提交于
      normally we deal with lock_mount()/umount races by checking that
      mountpoint to be is still in our namespace after lock_mount() has
      been done.  However, do_add_mount() skips that check when called
      with MNT_SHRINKABLE in flags (i.e. from finish_automount()).  The
      reason is that ->mnt_ns may be a temporary namespace created exactly
      to contain automounts a-la NFS4 referral handling.  It's not the
      namespace of the caller, though, so check_mnt() would fail here.
      We still need to check that ->mnt_ns is non-NULL in that case,
      though.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      156cacb1
  7. 31 7月, 2012 1 次提交
  8. 14 7月, 2012 4 次提交
  9. 31 5月, 2012 1 次提交
  10. 30 5月, 2012 1 次提交
    • A
      brlocks/lglocks: API cleanups · 962830df
      Andi Kleen 提交于
      lglocks and brlocks are currently generated with some complicated macros
      in lglock.h.  But there's no reason to not just use common utility
      functions and put all the data into a common data structure.
      
      In preparation, this patch changes the API to look more like normal
      function calls with pointers, not magic macros.
      
      The patch is rather large because I move over all users in one go to keep
      it bisectable.  This impacts the VFS somewhat in terms of lines changed.
      But no actual behaviour change.
      
      [akpm@linux-foundation.org: checkpatch fixes]
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      962830df
  11. 07 1月, 2012 4 次提交
  12. 04 1月, 2012 19 次提交