Hello Keith Busch,
The patch 492c5d455969: "block: bio-integrity: directly map user
buffers" from Nov 30, 2023 (linux-next), leads to the following
Smatch static checker warning:
block/bio-integrity.c:350 bio_integrity_map_user()
error: uninitialized symbol 'offset'.
block/bio-integrity.c
340 if (!bvec)
341 return -ENOMEM;
342 pages = NULL;
343 }
344
345 copy = !iov_iter_is_aligned(&iter, align, align);
346 ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset);
Smatch is concerned about the first "return 0;" if bytes or iter.count
is zero. In that situation then offset is uninitialized.
347 if (unlikely(ret < 0))
348 goto free_bvec;
349
--> 350 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
^^^^^^
351 if (pages != stack_pages)
352 kvfree(pages);
353 if (nr_bvecs > queue_max_integrity_segments(q))
354 copy = true;
355
356 if (copy)
357 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes,
358 direction, seed);
359 else
regards,
dan carpenter
