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authorPhillip Lougher <phillip@lougher.demon.co.uk>2009-03-04 19:31:12 -0500
committerPhillip Lougher <phillip@lougher.demon.co.uk>2009-03-04 19:31:12 -0500
commit118e1ef6fabfc023126e6075f6ac0fc729cb5285 (patch)
tree3c497ad9fcc5a459de9d75a688bb78c5220e8dd5 /fs
parent2450cf51a1bdba7037e91b1bcc494b01c58aaf66 (diff)
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 <phillip@lougher.demon.co.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/squashfs/block.c13
-rw-r--r--fs/squashfs/cache.c4
-rw-r--r--fs/squashfs/squashfs.h2
-rw-r--r--fs/squashfs/super.c2
4 files changed, 15 insertions, 6 deletions
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,
80 * generated a larger block - this does occasionally happen with zlib). 80 * generated a larger block - this does occasionally happen with zlib).
81 */ 81 */
82int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, 82int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
83 int length, u64 *next_index, int srclength) 83 int length, u64 *next_index, int srclength, int pages)
84{ 84{
85 struct squashfs_sb_info *msblk = sb->s_fs_info; 85 struct squashfs_sb_info *msblk = sb->s_fs_info;
86 struct buffer_head **bh; 86 struct buffer_head **bh;
@@ -185,6 +185,14 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
185 } 185 }
186 186
187 if (msblk->stream.avail_out == 0) { 187 if (msblk->stream.avail_out == 0) {
188 if (page == pages) {
189 ERROR("zlib_inflate tried to "
190 "decompress too much data, "
191 "expected %d bytes. Zlib "
192 "data probably corrupt\n",
193 srclength);
194 goto release_mutex;
195 }
188 msblk->stream.next_out = buffer[page++]; 196 msblk->stream.next_out = buffer[page++];
189 msblk->stream.avail_out = PAGE_CACHE_SIZE; 197 msblk->stream.avail_out = PAGE_CACHE_SIZE;
190 } 198 }
@@ -268,7 +276,8 @@ block_release:
268 put_bh(bh[k]); 276 put_bh(bh[k]);
269 277
270read_failure: 278read_failure:
271 ERROR("sb_bread failed reading block 0x%llx\n", cur_index); 279 ERROR("squashfs_read_data failed to read block 0x%llx\n",
280 (unsigned long long) index);
272 kfree(bh); 281 kfree(bh);
273 return -EIO; 282 return -EIO;
274} 283}
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,
119 119
120 entry->length = squashfs_read_data(sb, entry->data, 120 entry->length = squashfs_read_data(sb, entry->data,
121 block, length, &entry->next_index, 121 block, length, &entry->next_index,
122 cache->block_size); 122 cache->block_size, cache->pages);
123 123
124 spin_lock(&cache->lock); 124 spin_lock(&cache->lock);
125 125
@@ -406,7 +406,7 @@ int squashfs_read_table(struct super_block *sb, void *buffer, u64 block,
406 for (i = 0; i < pages; i++, buffer += PAGE_CACHE_SIZE) 406 for (i = 0; i < pages; i++, buffer += PAGE_CACHE_SIZE)
407 data[i] = buffer; 407 data[i] = buffer;
408 res = squashfs_read_data(sb, data, block, length | 408 res = squashfs_read_data(sb, data, block, length |
409 SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length); 409 SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length, pages);
410 kfree(data); 410 kfree(data);
411 return res; 411 return res;
412} 412}
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)
34 34
35/* block.c */ 35/* block.c */
36extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *, 36extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *,
37 int); 37 int, int);
38 38
39/* cache.c */ 39/* cache.c */
40extern struct squashfs_cache *squashfs_cache_init(char *, int, int); 40extern 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)
389 return err; 389 return err;
390 } 390 }
391 391
392 printk(KERN_INFO "squashfs: version 4.0 (2009/01/03) " 392 printk(KERN_INFO "squashfs: version 4.0 (2009/01/31) "
393 "Phillip Lougher\n"); 393 "Phillip Lougher\n");
394 394
395 return 0; 395 return 0;