Re: [PATCH 4/4] xfs_repair: fix left-shift overflows

Brian Foster
2015-10-09T13:24:48Z

On Thu, Oct 08, 2015 at 07:27:21PM -0500, Eric Sandeen wrote:
> pmask in struct parent_list is a __uint64_t, but in some places
> we populated it with "1LL << shift" where shift could be up
> to 63; this really needs to be a 1ULL type for this to be correct.
>
> Also spotted by libubsan...
>
> The code in prefetch.c has another issue with large fs blocks
> (32 or 64k) because it shifts by up to 128 bits, but that's left
> for later...
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> repair/incore_ino.c | 14 +++++++-------
> repair/prefetch.c | 2 +-
> 2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/repair/incore_ino.c b/repair/incore_ino.c
> index 32d7678..1898257 100644
> --- a/repair/incore_ino.c
> +++ b/repair/incore_ino.c
> @@ -625,7 +625,7 @@ set_inode_parent(
> else
> irec->ino_un.plist = ptbl;
>
> - ptbl->pmask = 1LL << offset;
> + ptbl->pmask = 1ULL << offset;
> ptbl->pentries = (xfs_ino_t*)memalign(sizeof(xfs_ino_t),
> sizeof(xfs_ino_t));
> if (!ptbl->pentries)
> @@ -638,8 +638,8 @@ set_inode_parent(
> return;
> }
>
> - if (ptbl->pmask & (1LL << offset)) {
> - bitmask = 1LL;
> + if (ptbl->pmask & (1ULL << offset)) {
> + bitmask = 1ULL;
> target = 0;
>
> for (i = 0; i < offset; i++) {
> @@ -655,7 +655,7 @@ set_inode_parent(
> return;
> }
>
> - bitmask = 1LL;
> + bitmask = 1ULL;
> cnt = target = 0;
>
> for (i = 0; i < XFS_INODES_PER_CHUNK; i++) {
> @@ -691,7 +691,7 @@ set_inode_parent(
> ptbl->cnt++;
> #endif
> ptbl->pentries[target] = parent;
> - ptbl->pmask |= (1LL << offset);
> + ptbl->pmask |= (1ULL << offset);
> }
>
> xfs_ino_t
> @@ -707,8 +707,8 @@ get_inode_parent(ino_tree_node_t *irec, int offset)
> else
> ptbl = irec->ino_un.plist;
>
> - if (ptbl->pmask & (1LL << offset)) {
> - bitmask = 1LL;
> + if (ptbl->pmask & (1ULL << offset)) {
> + bitmask = 1ULL;
> target = 0;
>
> for (i = 0; i < offset; i++) {
> diff --git a/repair/prefetch.c b/repair/prefetch.c
> index 52238ca..b11dcb3 100644
> --- a/repair/prefetch.c
> +++ b/repair/prefetch.c
> @@ -762,7 +762,7 @@ pf_queuing_worker(
> * sparse state in cluster sized chunks as cluster size
> * is the min. granularity of sparse irec regions.
> */
> - if ((sparse & ((1 << inodes_per_cluster) - 1)) == 0)
> + if ((sparse & ((1ULL << inodes_per_cluster) - 1)) == 0)
> pf_queue_io(args, &map, 1,
> (cur_irec->ino_isa_dir != 0) ?
> B_DIR_INODE : B_INODE);
> --
> 1.7.1
>
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