1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/pio_copy.c b/drivers/infiniband/hw/hfi1/pio_copy.c
index 8c25e1b58849..3a1ef3056282 100644
--- a/drivers/infiniband/hw/hfi1/pio_copy.c
+++ b/drivers/infiniband/hw/hfi1/pio_copy.c
@@ -771,6 +771,9 @@ void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
                         read_extra_bytes(pbuf, from, to_fill);
                         from += to_fill;
                         nbytes -= to_fill;
+                        /* may not be enough valid bytes left to align */
+                        if (extra > nbytes)
+                                extra = nbytes;
 
                         /* ...now write carry */
                         dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
@@ -798,6 +801,15 @@ void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
                         read_low_bytes(pbuf, from, extra);
                         from += extra;
                         nbytes -= extra;
+                        /*
+                         * If no bytes are left, return early - we are done.
+                         * NOTE: This short-circuit is *required* because
+                         * "extra" may have been reduced in size and "from"
+                         * is not aligned, as required when leaving this
+                         * if block.
+                         */
+                        if (nbytes == 0)
+                                return;
                 }
 
                 /* at this point, from is QW aligned */