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btrfs: fix potential overflow in cluster_pages_for_defrag on 32bit arch 

commit a1fbc6750e212c5675a4e48d7f51d44607eb8756 upstream.

On 32-bit systems, this shift will overflow for files larger than 4GB as
start_index is unsigned long while the calls to btrfs_delalloc_*_space
expect u64.

CC: stable@vger.kernel.org # 4.4+
Fixes: df480633b8 ("btrfs: extent-tree: Switch to new delalloc space reserve and release")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ define the variable instead of repeating the shift ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-10-04 19:04:26 +01:00 committed by Greg Kroah-Hartman
parent 9de4ffb701
commit 33e53f2cac
1 changed files with 4 additions and 6 deletions
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10
fs/btrfs/ioctl.c
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@ -1255,6 +1255,7 @@ static int cluster_pages_for_defrag(struct inode *inode,
u64 page_start;
u64 page_end;
u64 page_cnt;
u64 start = (u64)start_index << PAGE_SHIFT;
int ret;
int i;
int i_done;
@ -1271,8 +1272,7 @@ static int cluster_pages_for_defrag(struct inode *inode,
page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
start_index << PAGE_SHIFT,
page_cnt << PAGE_SHIFT);
start, page_cnt << PAGE_SHIFT);
if (ret)
return ret;
i_done = 0;
@ -1361,8 +1361,7 @@ again:
btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
spin_unlock(&BTRFS_I(inode)->lock);
btrfs_delalloc_release_space(inode, data_reserved,
start_index << PAGE_SHIFT,
(page_cnt - i_done) << PAGE_SHIFT, true);
start, (page_cnt - i_done) << PAGE_SHIFT, true);
}
@ -1389,8 +1388,7 @@ out:
put_page(pages[i]);
}
btrfs_delalloc_release_space(inode, data_reserved,
start_index << PAGE_SHIFT,
page_cnt << PAGE_SHIFT, true);
start, page_cnt << PAGE_SHIFT, true);
btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
extent_changeset_free(data_reserved);
return ret;