This is a note to let you know that I've just added the patch titled btrfs: fix potential overflow in cluster_pages_for_defrag on 32bit arch to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-fix-potential-overflow-in-cluster_pages_for_defrag-on-32bit-arch.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a1fbc6750e212c5675a4e48d7f51d44607eb8756 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Date: Sun, 4 Oct 2020 19:04:26 +0100 Subject: btrfs: fix potential overflow in cluster_pages_for_defrag on 32bit arch From: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx # 4.4+ Fixes: df480633b891 ("btrfs: extent-tree: Switch to new delalloc space reserve and release") Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> [ define the variable instead of repeating the shift ] Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/ioctl.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1261,6 +1261,7 @@ static int cluster_pages_for_defrag(stru u64 page_start; u64 page_end; u64 page_cnt; + u64 start = (u64)start_index << PAGE_SHIFT; int ret; int i; int i_done; @@ -1277,8 +1278,7 @@ static int cluster_pages_for_defrag(stru page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1); ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved, - start_index << PAGE_SHIFT, - page_cnt << PAGE_SHIFT); + start, page_cnt << PAGE_SHIFT); if (ret) return ret; i_done = 0; @@ -1367,8 +1367,7 @@ again: btrfs_mod_outstanding_extents(BTRFS_I(inode), 1); spin_unlock(&BTRFS_I(inode)->lock); btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, - start_index << PAGE_SHIFT, - (page_cnt - i_done) << PAGE_SHIFT, true); + start, (page_cnt - i_done) << PAGE_SHIFT, true); } @@ -1395,8 +1394,7 @@ out: put_page(pages[i]); } btrfs_delalloc_release_space(BTRFS_I(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; Patches currently in stable-queue which might be from willy@xxxxxxxxxxxxx are queue-5.9/btrfs-fix-potential-overflow-in-cluster_pages_for_defrag-on-32bit-arch.patch