Sizing the buffer based on block size is incorrect, leading to a potential buffer over-run on 4K block size file systems (because the metadata block size is always 8K). This bug doesn't seem have triggered because 4K block size file systems are not default, and also because metadata blocks after compression tend to be less than 4K. Signed-off-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxxxxxx> --- fs/squashfs/block.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index 1cb0d81..653c030 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -87,9 +87,8 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, u64 cur_index = index >> msblk->devblksize_log2; int bytes, compressed, b = 0, k = 0, page = 0, avail; - - bh = kcalloc((msblk->block_size >> msblk->devblksize_log2) + 1, - sizeof(*bh), GFP_KERNEL); + bh = kcalloc(((srclength + msblk->devblksize - 1) + >> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL); if (bh == NULL) return -ENOMEM; -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
