1. 20 Sep, 2017 37 commits
  2. 13 Sep, 2017 3 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.13.2 · 07dd6cc1
      Greg Kroah-Hartman authored
      07dd6cc1
    • Richard Wareing's avatar
      xfs: XFS_IS_REALTIME_INODE() should be false if no rt device present · 24cb3325
      Richard Wareing authored
      commit b31ff3cd upstream.
      
      If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on
      a directory in a filesystem that does not have a realtime device and
      create a new file in that directory, it gets marked as a real time file.
      When data is written and a fsync is issued, the filesystem attempts to
      flush a non-existent rt device during the fsync process.
      
      This results in a crash dereferencing a null buftarg pointer in
      xfs_blkdev_issue_flush():
      
        BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
        IP: xfs_blkdev_issue_flush+0xd/0x20
        .....
        Call Trace:
          xfs_file_fsync+0x188/0x1c0
          vfs_fsync_range+0x3b/0xa0
          do_fsync+0x3d/0x70
          SyS_fsync+0x10/0x20
          do_syscall_64+0x4d/0xb0
          entry_SYSCALL64_slow_path+0x25/0x25
      
      Setting RT inode flags does not require special privileges so any
      unprivileged user can cause this oops to occur.  To reproduce, confirm
      kernel is compiled with CONFIG_XFS_RT=y and run:
      
        # mkfs.xfs -f /dev/pmem0
        # mount /dev/pmem0 /mnt/test
        # mkdir /mnt/test/foo
        # xfs_io -c 'chattr +t' /mnt/test/foo
        # xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar
      
      Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait.
      
      Kernels built with CONFIG_XFS_RT=n are not exposed to this bug.
      
      Fixes: f538d4da ("[XFS] write barrier support")
      Signed-off-by: default avatarRichard Wareing <rwareing@fb.com>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      24cb3325
    • Trond Myklebust's avatar
      NFSv4: Fix up mirror allocation · 41a5f0a2
      Trond Myklebust authored
      commit 14abcb0b upstream.
      
      There are a number of callers of nfs_pageio_complete() that want to
      continue using the nfs_pageio_descriptor without needing to call
      nfs_pageio_init() again. Examples include nfs_pageio_resend() and
      nfs_pageio_cond_complete().
      
      The problem is that nfs_pageio_complete() also calls
      nfs_pageio_cleanup_mirroring(), which frees up the array of mirrors.
      This can lead to writeback errors, in the next call to
      nfs_pageio_setup_mirroring().
      
      Fix by simply moving the allocation of the mirrors to
      nfs_pageio_setup_mirroring().
      
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=196709Reported-by: default avatarJianhongYin <yin-jianhong@163.com>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      41a5f0a2