1. 09 Mar, 2016 2 commits
    • Jeff Layton's avatar
      locks: fix unlock when fcntl_setlk races with a close · 7b667ced
      Jeff Layton authored
      commit 7f3697e2 upstream.
      
      Dmitry reported that he was able to reproduce the WARN_ON_ONCE that
      fires in locks_free_lock_context when the flc_posix list isn't empty.
      
      The problem turns out to be that we're basically rebuilding the
      file_lock from scratch in fcntl_setlk when we discover that the setlk
      has raced with a close. If the l_whence field is SEEK_CUR or SEEK_END,
      then we may end up with fl_start and fl_end values that differ from
      when the lock was initially set, if the file position or length of the
      file has changed in the interim.
      
      Fix this by just reusing the same lock request structure, and simply
      override fl_type value with F_UNLCK as appropriate. That ensures that
      we really are unlocking the lock that was initially set.
      
      While we're there, make sure that we do pop a WARN_ON_ONCE if the
      removal ever fails. Also return -EBADF in this event, since that's
      what we would have returned if the close had happened earlier.
      
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Fixes: c293621b (stale POSIX lock handling)
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarJeff Layton <jeff.layton@primarydata.com>
      Acked-by: default avatar"J. Bruce Fields" <bfields@fieldses.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7b667ced
    • Hannes Reinecke's avatar
      bio: return EINTR if copying to user space got interrupted · 8a3b2a49
      Hannes Reinecke authored
      commit 2d99b55d upstream.
      
      Commit 35dc2483 introduced a check for
      current->mm to see if we have a user space context and only copies data
      if we do. Now if an IO gets interrupted by a signal data isn't copied
      into user space any more (as we don't have a user space context) but
      user space isn't notified about it.
      
      This patch modifies the behaviour to return -EINTR from bio_uncopy_user()
      to notify userland that a signal has interrupted the syscall, otherwise
      it could lead to a situation where the caller may get a buffer with
      no data returned.
      
      This can be reproduced by issuing SG_IO ioctl()s in one thread while
      constantly sending signals to it.
      
      Fixes: 35dc2483 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
      Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: stable@vger.kernel.org # v.3.11+
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8a3b2a49
  2. 03 Mar, 2016 38 commits