lkml.org 
[lkml]   [2018]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 18/52] ext4: fix fencepost error in check for inode count overflow during resize
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Jan Kara <jack@suse.cz>

    commit 4f2f76f751433908364ccff82f437a57d0e6e9b7 upstream.

    ext4_resize_fs() has an off-by-one bug when checking whether growing of
    a filesystem will not overflow inode count. As a result it allows a
    filesystem with 8192 inodes per group to grow to 64TB which overflows
    inode count to 0 and makes filesystem unusable. Fix it.

    Cc: stable@vger.kernel.org
    Fixes: 3f8a6411fbada1fa482276591e037f3b1adcf55b
    Reported-by: Jaco Kroon <jaco@uls.co.za>
    Signed-off-by: Jan Kara <jack@suse.cz>
    Signed-off-by: Theodore Ts'o <tytso@mit.edu>
    Reviewed-by: Andreas Dilger <adilger@dilger.ca>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    fs/ext4/resize.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/fs/ext4/resize.c
    +++ b/fs/ext4/resize.c
    @@ -1905,7 +1905,7 @@ retry:
    return 0;

    n_group = ext4_get_group_number(sb, n_blocks_count - 1);
    - if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
    + if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
    ext4_warning(sb, "resize would cause inodes_count overflow");
    return -EINVAL;
    }

    \
     
     \ /
      Last update: 2018-06-24 18:30    [W:4.054 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site