From 118e1ef6fabfc023126e6075f6ac0fc729cb5285 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 5 Mar 2009 00:31:12 +0000 Subject: Squashfs: Fix oops when reading fsfuzzer corrupted filesystems This fixes a code regression caused by the recent mainlining changes. The recent code changes call zlib_inflate repeatedly, decompressing into separate 4K buffers, this code didn't check for the possibility that zlib_inflate might ask for too many buffers when decompressing corrupted data. Signed-off-by: Phillip Lougher --- fs/squashfs/block.c | 13 +++++++++++-- fs/squashfs/cache.c | 4 ++-- fs/squashfs/squashfs.h | 2 +- fs/squashfs/super.c | 2 +- 4 files changed, 15 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index c837dfc2b3c6..321728f48f2d 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -80,7 +80,7 @@ static struct buffer_head *get_block_length(struct super_block *sb, * generated a larger block - this does occasionally happen with zlib). */ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, - int length, u64 *next_index, int srclength) + int length, u64 *next_index, int srclength, int pages) { struct squashfs_sb_info *msblk = sb->s_fs_info; struct buffer_head **bh; @@ -185,6 +185,14 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, } if (msblk->stream.avail_out == 0) { + if (page == pages) { + ERROR("zlib_inflate tried to " + "decompress too much data, " + "expected %d bytes. Zlib " + "data probably corrupt\n", + srclength); + goto release_mutex; + } msblk->stream.next_out = buffer[page++]; msblk->stream.avail_out = PAGE_CACHE_SIZE; } @@ -268,7 +276,8 @@ block_release: put_bh(bh[k]); read_failure: - ERROR("sb_bread failed reading block 0x%llx\n", cur_index); + ERROR("squashfs_read_data failed to read block 0x%llx\n", + (unsigned long long) index); kfree(bh); return -EIO; } diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c index f29eda16d25e..1c4739e33af6 100644 --- a/fs/squashfs/cache.c +++ b/fs/squashfs/cache.c @@ -119,7 +119,7 @@ struct squashfs_cache_entry *squashfs_cache_get(struct super_block *sb, entry->length = squashfs_read_data(sb, entry->data, block, length, &entry->next_index, - cache->block_size); + cache->block_size, cache->pages); spin_lock(&cache->lock); @@ -406,7 +406,7 @@ int squashfs_read_table(struct super_block *sb, void *buffer, u64 block, for (i = 0; i < pages; i++, buffer += PAGE_CACHE_SIZE) data[i] = buffer; res = squashfs_read_data(sb, data, block, length | - SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length); + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length, pages); kfree(data); return res; } diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index 6b2515d027d5..0e9feb6adf7e 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -34,7 +34,7 @@ static inline struct squashfs_inode_info *squashfs_i(struct inode *inode) /* block.c */ extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *, - int); + int, int); /* cache.c */ extern struct squashfs_cache *squashfs_cache_init(char *, int, int); diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 071df5b5b491..681ec0d83799 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -389,7 +389,7 @@ static int __init init_squashfs_fs(void) return err; } - printk(KERN_INFO "squashfs: version 4.0 (2009/01/03) " + printk(KERN_INFO "squashfs: version 4.0 (2009/01/31) " "Phillip Lougher\n"); return 0; -- cgit v1.2.3