ext4: add explicit casts when masking cluster sizes
commit f5a44db5d2d677dfbf12deee461f85e9ec633961 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5aae3d1..7bb2e2e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -280,6 +280,16 @@
/* Translate # of blks to # of clusters */
#define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
(sbi)->s_cluster_bits)
+/* Mask out the low bits to get the starting block of the cluster */
+#define EXT4_PBLK_CMASK(s, pblk) ((pblk) & \
+ ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
+#define EXT4_LBLK_CMASK(s, lblk) ((lblk) & \
+ ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
+/* Get the cluster offset */
+#define EXT4_PBLK_COFF(s, pblk) ((pblk) & \
+ ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
+#define EXT4_LBLK_COFF(s, lblk) ((lblk) & \
+ ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
/*
* Structure of a blocks group descriptor
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d480d49..ecabf00 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1772,8 +1772,7 @@
depth = ext_depth(inode);
if (!path[depth].p_ext)
goto out;
- b2 = le32_to_cpu(path[depth].p_ext->ee_block);
- b2 &= ~(sbi->s_cluster_ratio - 1);
+ b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
/*
* get the next allocated block if the extent in the path
@@ -1783,7 +1782,7 @@
b2 = ext4_ext_next_allocated_block(path);
if (b2 == EXT_MAX_BLOCKS)
goto out;
- b2 &= ~(sbi->s_cluster_ratio - 1);
+ b2 = EXT4_LBLK_CMASK(sbi, b2);
}
/* check for wrap through zero on extent logical start block*/
@@ -2444,7 +2443,7 @@
* truncate operation has removed all of the blocks in
* the cluster.
*/
- if (pblk & (sbi->s_cluster_ratio - 1) &&
+ if (EXT4_PBLK_COFF(sbi, pblk) &&
(ee_len == num))
*partial_cluster = EXT4_B2C(sbi, pblk);
else
@@ -3675,7 +3674,7 @@
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t lblk_start, lblk_end;
- lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
+ lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
@@ -3734,9 +3733,9 @@
trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
/* Check towards left side */
- c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
+ c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
if (c_offset) {
- lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
+ lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
lblk_to = lblk_from + c_offset - 1;
if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
@@ -3744,7 +3743,7 @@
}
/* Now check towards right. */
- c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
+ c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
if (allocated_clusters && c_offset) {
lblk_from = lblk_start + num_blks;
lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
@@ -3952,7 +3951,7 @@
struct ext4_ext_path *path)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
+ ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
ext4_lblk_t ex_cluster_start, ex_cluster_end;
ext4_lblk_t rr_cluster_start;
ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
@@ -3970,8 +3969,7 @@
(rr_cluster_start == ex_cluster_start)) {
if (rr_cluster_start == ex_cluster_end)
ee_start += ee_len - 1;
- map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
- c_offset;
+ map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
map->m_len = min(map->m_len,
(unsigned) sbi->s_cluster_ratio - c_offset);
/*
@@ -4125,7 +4123,7 @@
*/
map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
newex.ee_block = cpu_to_le32(map->m_lblk);
- cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
+ cluster_offset = EXT4_LBLK_CMASK(sbi, map->m_lblk);
/*
* If we are doing bigalloc, check to see if the extent returned
@@ -4193,7 +4191,7 @@
* needed so that future calls to get_implied_cluster_alloc()
* work correctly.
*/
- offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
+ offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
ar.goal -= offset;
ar.logical -= offset;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c1f58e0..4c0e3e02 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4107,7 +4107,7 @@
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;
@@ -4644,7 +4644,7 @@
* 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;
@@ -4658,7 +4658,7 @@
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)