Commit e0d1f700 authored Apr 23, 2010 by Phillip Lougher

squashfs: fix potential buffer over-run on 4K block file systems



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@lougher.demon.co.uk>

parent 370ec3d1

fs/squashfs/block.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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;

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