4.19-stable review patch. If anyone has any objections, please let me know.
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From: Nikolay Borisov nborisov@suse.com
commit 139a56170de67101791d6e6c8e940c6328393fe9 upstream.
qgroup_rsv_size is calculated as the product of outstanding_extent * fs_info->nodesize. The product is calculated with 32 bit precision since both variables are defined as u32. Yet qgroup_rsv_size expects a 64 bit result.
Avoid possible multiplication overflow by casting outstanding_extent to u64. Such overflow would in the worst case (64K nodesize) require more than 65536 extents, which is quite large and i'ts not likely that it would happen in practice.
Fixes-coverity-id: 1435101 Fixes: ff6bc37eb7f6 ("btrfs: qgroup: Use independent and accurate per inode qgroup rsv") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Nikolay Borisov nborisov@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/extent-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5872,7 +5872,7 @@ static void btrfs_calculate_inode_block_ * * This is overestimating in most cases. */ - qgroup_rsv_size = outstanding_extents * fs_info->nodesize; + qgroup_rsv_size = (u64)outstanding_extents * fs_info->nodesize;
spin_lock(&block_rsv->lock); block_rsv->size = reserve_size;