ext4: Fix wrong comparisons in mext_check_arguments()
From: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
mext_check_arguments() in move_extents.c has wrong comparisons.
orig_start which is passed from user-space is block unit,
but i_size of inode is byte unit, therefore the checks do not work fine.
This mis-check leads to the overflow of 'len' and then hits BUG_ON()
in ext4_move_extens(). The patch fixes this issue.
Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
---
fs/ext4/move_extent.c | 39 ++++++++++++++++++++++++---------------
1 files changed, 24 insertions(+), 15 deletions(-)
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 5821e0b..60ed567 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -972,43 +972,52 @@ mext_check_arguments(struct inode *orig_inode,
}
if (orig_inode->i_size > donor_inode->i_size) {
- if (orig_start >= donor_inode->i_size) {
+ if (orig_start << orig_inode->i_blkbits >=
+ donor_inode->i_size) {
ext4_debug("ext4 move extent: orig start offset "
"[%llu] should be less than donor file size "
"[%lld] [ino:orig %lu, donor_inode %lu]\n",
- orig_start, donor_inode->i_size,
- orig_inode->i_ino, donor_inode->i_ino);
+ orig_start << orig_inode->i_blkbits,
+ donor_inode->i_size, orig_inode->i_ino,
+ donor_inode->i_ino);
return -EINVAL;
}
-
- if (orig_start + *len > donor_inode->i_size) {
+ if ((orig_start + *len) << orig_inode->i_blkbits >
+ donor_inode->i_size) {
ext4_debug("ext4 move extent: End offset [%llu] should "
"be less than donor file size [%lld]."
"So adjust length from %llu to %lld "
"[ino:orig %lu, donor %lu]\n",
- orig_start + *len, donor_inode->i_size,
- *len, donor_inode->i_size - orig_start,
+ (orig_start + *len) << orig_inode->i_blkbits,
+ donor_inode->i_size,
+ *len, (donor_inode->i_size >>
+ orig_inode->i_blkbits) - orig_start,
orig_inode->i_ino, donor_inode->i_ino);
- *len = donor_inode->i_size - orig_start;
+ *len = (donor_inode->i_size >> orig_inode->i_blkbits) -
+ orig_start;
}
} else {
- if (orig_start >= orig_inode->i_size) {
+ if (orig_start << orig_inode->i_blkbits >=
+ orig_inode->i_size) {
ext4_debug("ext4 move extent: start offset [%llu] "
"should be less than original file size "
"[%lld] [inode:orig %lu, donor %lu]\n",
- orig_start, orig_inode->i_size,
- orig_inode->i_ino, donor_inode->i_ino);
+ orig_start << orig_inode->i_blkbits,
+ orig_inode->i_size, orig_inode->i_ino,
+ donor_inode->i_ino);
return -EINVAL;
}
-
- if (orig_start + *len > orig_inode->i_size) {
+ if ((orig_start + *len) << orig_inode->i_blkbits >
+ orig_inode->i_size) {
ext4_debug("ext4 move extent: Adjust length "
"from %llu to %lld. Because it should be "
"less than original file size "
"[ino:orig %lu, donor %lu]\n",
- *len, orig_inode->i_size - orig_start,
+ *len, (orig_inode->i_size >>
+ orig_inode->i_blkbits) - orig_start,
orig_inode->i_ino, donor_inode->i_ino);
- *len = orig_inode->i_size - orig_start;
+ *len = (orig_inode->i_size >> orig_inode->i_blkbits) -
+ orig_start;
}
}
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