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/extents.c b/fs/ext4/extents.c
index 267c9fb..4410cc3 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1851,8 +1851,7 @@
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
@@ -1862,7 +1861,7 @@
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*/
@@ -2521,7 +2520,7 @@
* extent, we have to mark the cluster as used (store negative
* cluster number in partial_cluster).
*/
- unaligned = pblk & (sbi->s_cluster_ratio - 1);
+ unaligned = EXT4_PBLK_COFF(sbi, pblk);
if (unaligned && (ee_len == num) &&
(*partial_cluster != -((long long)EXT4_B2C(sbi, pblk))))
*partial_cluster = EXT4_B2C(sbi, pblk);
@@ -2615,7 +2614,7 @@
* accidentally freeing it later on
*/
pblk = ext4_ext_pblock(ex);
- if (pblk & (sbi->s_cluster_ratio - 1))
+ if (EXT4_PBLK_COFF(sbi, pblk))
*partial_cluster =
-((long long)EXT4_B2C(sbi, pblk));
ex--;
@@ -3770,7 +3769,7 @@
{
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);
@@ -3829,9 +3828,9 @@
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))
@@ -3839,7 +3838,7 @@
}
/* 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;
@@ -4047,7 +4046,7 @@
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);
@@ -4065,8 +4064,7 @@
(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);
/*
@@ -4220,7 +4218,7 @@
*/
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
@@ -4288,7 +4286,7 @@
* 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;