4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jerry Lee <jerrylee@xxxxxxxx> commit aec51758ce10a9c847a62a48a168f8c804c6e053 upstream. On a 32-bit platform, the value of n_blcoks_count may be wrong during the file system is resized to size larger than 2^32 blocks. This may caused the superblock being corrupted with zero blocks count. Fixes: 1c6bd7173d66 Signed-off-by: Jerry Lee <jerrylee@xxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/resize.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1926,7 +1926,8 @@ retry: n_desc_blocks = o_desc_blocks + le16_to_cpu(es->s_reserved_gdt_blocks); n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); - n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb); + n_blocks_count = (ext4_fsblk_t)n_group * + EXT4_BLOCKS_PER_GROUP(sb); n_group--; /* set to last group number */ }