From f3065f60ddfd4b5e34a412851d91d0cf27cdbf7e Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 5 Aug 2010 04:51:50 +0100 Subject: [PATCH] Squashfs: fix block size use in LZO decompressor Sizing the buffer using block size alone is incorrect leading to a potential buffer over-run on 4K block size file systems (because the metadata block size is always 8K). Srclength is set to the maximum expected size of the decompressed block and it is block_size or 8K depending on whether a data or metadata block is being decompressed. Signed-off-by: Phillip Lougher --- fs/squashfs/lzo_wrapper.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c index e1f86ded0ee5..5d87789bf1c1 100644 --- a/fs/squashfs/lzo_wrapper.c +++ b/fs/squashfs/lzo_wrapper.c @@ -40,13 +40,15 @@ struct squashfs_lzo { static void *lzo_init(struct squashfs_sb_info *msblk) { + int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); + struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL); if (stream == NULL) goto failed; - stream->input = vmalloc(msblk->block_size); + stream->input = vmalloc(block_size); if (stream->input == NULL) goto failed; - stream->output = vmalloc(msblk->block_size); + stream->output = vmalloc(block_size); if (stream->output == NULL) goto failed2; @@ -80,7 +82,7 @@ static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer, struct squashfs_lzo *stream = msblk->stream; void *buff = stream->input; int avail, i, bytes = length, res; - size_t out_len = msblk->block_size; + size_t out_len = srclength; mutex_lock(&msblk->read_data_mutex);