ext4: add explicit casts when masking cluster sizes
The missing casts can cause the high 64-bits of the physical blocks to
be lost. Set up new macros which allows us to make sure the right
thing happen, even if at some point we end up supporting larger
logical block numbers.
Thanks to the Emese Revfy and the PaX security team for reporting this
issue.
Reported-by: PaX Team <pageexec@freemail.hu>
Reported-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 04766d9..04a5c75 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4126,7 +4126,7 @@
ext4_get_group_no_and_offset(sb, goal, &group, &block);
/* set up allocation goals */
- ac->ac_b_ex.fe_logical = ar->logical & ~(sbi->s_cluster_ratio - 1);
+ ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
ac->ac_status = AC_STATUS_CONTINUE;
ac->ac_sb = sb;
ac->ac_inode = ar->inode;
@@ -4668,7 +4668,7 @@
* blocks at the beginning or the end unless we are explicitly
* requested to avoid doing so.
*/
- overflow = block & (sbi->s_cluster_ratio - 1);
+ overflow = EXT4_PBLK_COFF(sbi, block);
if (overflow) {
if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
overflow = sbi->s_cluster_ratio - overflow;
@@ -4682,7 +4682,7 @@
count += overflow;
}
}
- overflow = count & (sbi->s_cluster_ratio - 1);
+ overflow = EXT4_LBLK_COFF(sbi, count);
if (overflow) {
if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
if (count > overflow)