From 70d5d3dcea47c16058d2b093c29e07fdf61b56ad Mon Sep 17 00:00:00 2001 From: Akira Fujita Date: Wed, 16 Sep 2009 14:28:22 -0400 Subject: [PATCH] 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: Akira Fujita Reviewed-by: Greg Freemyer Signed-off-by: "Theodore Ts'o" --- fs/ext4/move_extent.c | 46 +++++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 19 deletions(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 5821e0bee917..c593eb2b193a 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -898,6 +898,10 @@ mext_check_arguments(struct inode *orig_inode, struct inode *donor_inode, __u64 orig_start, __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 */ if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { ext4_debug("ext4 move extent: The argument files should be " @@ -972,43 +976,47 @@ mext_check_arguments(struct inode *orig_inode, } 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 " - "[%llu] should be less than donor file size " - "[%lld] [ino:orig %lu, donor_inode %lu]\n", - orig_start, donor_inode->i_size, + "[%llu] should be less than donor file blocks " + "[%u] [ino:orig %lu, donor %lu]\n", + orig_start, donor_blocks, orig_inode->i_ino, donor_inode->i_ino); 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 " - "be less than donor file size [%lld]." - "So adjust length from %llu to %lld " + "be less than donor file blocks [%u]." + "So adjust length from %llu to %llu " "[ino:orig %lu, donor %lu]\n", - orig_start + *len, donor_inode->i_size, - *len, donor_inode->i_size - orig_start, + orig_start + *len, donor_blocks, + *len, donor_blocks - orig_start, orig_inode->i_ino, donor_inode->i_ino); - *len = donor_inode->i_size - orig_start; + *len = donor_blocks - orig_start; } } 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] " - "should be less than original file size " - "[%lld] [inode:orig %lu, donor %lu]\n", - orig_start, orig_inode->i_size, + "should be less than original file blocks " + "[%u] [ino:orig %lu, donor %lu]\n", + orig_start, orig_blocks, orig_inode->i_ino, donor_inode->i_ino); return -EINVAL; } - if (orig_start + *len > orig_inode->i_size) { + if (orig_start + *len > orig_blocks) { ext4_debug("ext4 move extent: Adjust length " - "from %llu to %lld. Because it should be " - "less than original file size " + "from %llu to %llu. Because it should be " + "less than original file blocks " "[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); - *len = orig_inode->i_size - orig_start; + *len = orig_blocks - orig_start; } } -- 2.20.1