udf: Fix 64-bit sign extension issues affecting blocks > 0x7FFFFFFF
Large (> 1 TiB) UDF filesystems appear subject to several problems when
mounted on 64-bit systems:
* readdir() can fail on a directory containing File Identifiers residing
above 0x7FFFFFFF. This manifests as a 'ls' command failing with EIO.
* FIBMAP on a file block located above 0x7FFFFFFF can return a negative
value. The low 32 bits are correct, but applications that don't mask the
high 32 bits of the result can perform incorrectly.
Per suggestion by Jan Kara, introduce a udf_pblk_t type for representation
of UDF block addresses. Ultimately, all driver functions that manipulate
UDF block addresses should use this type; for now, deployment is limited
to functions with actual or potential sign extension issues.
Changes to udf_readdir() and udf_block_map() address the issues noted
above; other changes address potential similar issues uncovered during
audit of the driver code.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 08bf097..7ea0592 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -2389,7 +2389,7 @@ static unsigned int udf_count_free_bitmap(struct super_block *sb,
struct buffer_head *bh = NULL;
unsigned int accum = 0;
int index;
- int block = 0, newblock;
+ udf_pblk_t block = 0, newblock;
struct kernel_lb_addr loc;
uint32_t bytes;
uint8_t *ptr;
