• Anand Jain's avatar
    btrfs: fix null pointer dereference in btrfs_show_devname when name is null · 0aeb8a6e
    Anand Jain authored
    dev->name is null but missing flag is not set.
    Strictly speaking the missing flag should have been set, but there
    are more places where code just checks if name is null. For now this
    patch does the same.
    
    stack:
    BUG: unable to handle kernel NULL pointer dereference at 0000000000000064
    IP: [<ffffffffa0228908>] btrfs_show_devname+0x58/0xf0 [btrfs]
    
    [<ffffffff81198879>] show_vfsmnt+0x39/0x130
    [<ffffffff81178056>] m_show+0x16/0x20
    [<ffffffff8117d706>] seq_read+0x296/0x390
    [<ffffffff8115aa7d>] vfs_read+0x9d/0x160
    [<ffffffff8115b549>] SyS_read+0x49/0x90
    [<ffffffff817abe52>] system_call_fastpath+0x16/0x1b
    
    reproducer:
    mkfs.btrfs -draid1 -mraid1 /dev/sdg1 /dev/sdg2
    btrfstune -S 1 /dev/sdg1
    modprobe -r btrfs && modprobe btrfs
    mount -o degraded /dev/sdg1 /btrfs
    btrfs dev add /dev/sdg3 /btrfs
    Signed-off-by: default avatarAnand Jain <Anand.Jain@oracle.com>
    Signed-off-by: default avatarChris Mason <clm@fb.com>
    0aeb8a6e
super.c 52.2 KB