Commit 70d5d3dc authored by Akira Fujita's avatar Akira Fujita Committed by Theodore Ts'o

ext4: Fix wrong comparisons in mext_check_arguments()

The mext_check_arguments() function 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_extents().  The patch fixes this issue.
Signed-off-by: default avatarAkira Fujita <a-fujita@rs.jp.nec.com>
Reviewed-by: default avatarGreg Freemyer <greg.freemyer@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 5f3481e9
...@@ -898,6 +898,10 @@ mext_check_arguments(struct inode *orig_inode, ...@@ -898,6 +898,10 @@ mext_check_arguments(struct inode *orig_inode,
struct inode *donor_inode, __u64 orig_start, struct inode *donor_inode, __u64 orig_start,
__u64 donor_start, __u64 *len, __u64 moved_len) __u64 donor_start, __u64 *len, __u64 moved_len)
{ {
ext4_lblk_t orig_blocks, donor_blocks;
unsigned int blkbits = orig_inode->i_blkbits;
unsigned int blocksize = 1 << blkbits;
/* Regular file check */ /* Regular file check */
if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
ext4_debug("ext4 move extent: The argument files should be " ext4_debug("ext4 move extent: The argument files should be "
...@@ -972,43 +976,47 @@ mext_check_arguments(struct inode *orig_inode, ...@@ -972,43 +976,47 @@ mext_check_arguments(struct inode *orig_inode,
} }
if (orig_inode->i_size > donor_inode->i_size) { if (orig_inode->i_size > donor_inode->i_size) {
if (orig_start >= donor_inode->i_size) { donor_blocks = (donor_inode->i_size + blocksize - 1) >> blkbits;
/* TODO: eliminate this artificial restriction */
if (orig_start >= donor_blocks) {
ext4_debug("ext4 move extent: orig start offset " ext4_debug("ext4 move extent: orig start offset "
"[%llu] should be less than donor file size " "[%llu] should be less than donor file blocks "
"[%lld] [ino:orig %lu, donor_inode %lu]\n", "[%u] [ino:orig %lu, donor %lu]\n",
orig_start, donor_inode->i_size, orig_start, donor_blocks,
orig_inode->i_ino, donor_inode->i_ino); orig_inode->i_ino, donor_inode->i_ino);
return -EINVAL; return -EINVAL;
} }
if (orig_start + *len > donor_inode->i_size) { /* TODO: eliminate this artificial restriction */
if (orig_start + *len > donor_blocks) {
ext4_debug("ext4 move extent: End offset [%llu] should " ext4_debug("ext4 move extent: End offset [%llu] should "
"be less than donor file size [%lld]." "be less than donor file blocks [%u]."
"So adjust length from %llu to %lld " "So adjust length from %llu to %llu "
"[ino:orig %lu, donor %lu]\n", "[ino:orig %lu, donor %lu]\n",
orig_start + *len, donor_inode->i_size, orig_start + *len, donor_blocks,
*len, donor_inode->i_size - orig_start, *len, donor_blocks - orig_start,
orig_inode->i_ino, donor_inode->i_ino); orig_inode->i_ino, donor_inode->i_ino);
*len = donor_inode->i_size - orig_start; *len = donor_blocks - orig_start;
} }
} else { } else {
if (orig_start >= orig_inode->i_size) { orig_blocks = (orig_inode->i_size + blocksize - 1) >> blkbits;
if (orig_start >= orig_blocks) {
ext4_debug("ext4 move extent: start offset [%llu] " ext4_debug("ext4 move extent: start offset [%llu] "
"should be less than original file size " "should be less than original file blocks "
"[%lld] [inode:orig %lu, donor %lu]\n", "[%u] [ino:orig %lu, donor %lu]\n",
orig_start, orig_inode->i_size, orig_start, orig_blocks,
orig_inode->i_ino, donor_inode->i_ino); orig_inode->i_ino, donor_inode->i_ino);
return -EINVAL; return -EINVAL;
} }
if (orig_start + *len > orig_inode->i_size) { if (orig_start + *len > orig_blocks) {
ext4_debug("ext4 move extent: Adjust length " ext4_debug("ext4 move extent: Adjust length "
"from %llu to %lld. Because it should be " "from %llu to %llu. Because it should be "
"less than original file size " "less than original file blocks "
"[ino:orig %lu, donor %lu]\n", "[ino:orig %lu, donor %lu]\n",
*len, orig_inode->i_size - orig_start, *len, orig_blocks - orig_start,
orig_inode->i_ino, donor_inode->i_ino); orig_inode->i_ino, donor_inode->i_ino);
*len = orig_inode->i_size - orig_start; *len = orig_blocks - orig_start;
} }
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment