Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-02-02-v2' into staging

nbd patches for 2021-02-02

- more cleanup from iotest python conversion
- progress towards consistent use of signed 64-bit types through block layer
- fix some crashes related to NBD reconnect

# gpg: Signature made Wed 03 Feb 2021 14:20:01 GMT
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2021-02-02-v2:
  nbd: make nbd_read* return -EIO on error
  block/nbd: only enter connection coroutine if it's present
  block/nbd: only detach existing iochannel from aio_context
  block/io: use int64_t bytes in copy_range
  block/io: support int64_t bytes in read/write wrappers
  block/io: support int64_t bytes in bdrv_co_p{read,write}v_part()
  block/io: support int64_t bytes in bdrv_aligned_preadv()
  block/io: support int64_t bytes in bdrv_co_do_copy_on_readv()
  block/io: support int64_t bytes in bdrv_aligned_pwritev()
  block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes()
  block/io: use int64_t bytes in driver wrappers
  block: use int64_t as bytes type in tracked requests
  block/io: improve bdrv_check_request: check qiov too
  block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes
  block/io: bdrv_pad_request(): support qemu_iovec_init_extended failure
  block/io: refactor bdrv_pad_request(): move bdrv_pad_request() up
  block: fix theoretical overflow in bdrv_init_padding()
  util/iov: make qemu_iovec_init_extended() honest
  block: refactor bdrv_check_request: add errp
  iotests: Fix expected whitespace for 185

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 23 insertions, 2 deletions

diff --git a/util/iov.c b/util/iov.c
index f3a9e92a37..58c7b3eeee 100644
--- a/util/iov.c
+++ b/util/iov.c
@@ -415,7 +415,7 @@ int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len)
  * Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov,
  * and @tail_buf buffer into new qiov.
  */
-void qemu_iovec_init_extended(
+int qemu_iovec_init_extended(
         QEMUIOVector *qiov,
         void *head_buf, size_t head_len,
         QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
@@ -425,12 +425,24 @@ void qemu_iovec_init_extended(
     int total_niov, mid_niov = 0;
     struct iovec *p, *mid_iov = NULL;
 
+    assert(mid_qiov->niov <= IOV_MAX);
+
+    if (SIZE_MAX - head_len < mid_len ||
+        SIZE_MAX - head_len - mid_len < tail_len)
+    {
+        return -EINVAL;
+    }
+
     if (mid_len) {
         mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len,
                              &mid_head, &mid_tail, &mid_niov);
     }
 
     total_niov = !!head_len + mid_niov + !!tail_len;
+    if (total_niov > IOV_MAX) {
+        return -EINVAL;
+    }
+
     if (total_niov == 1) {
         qemu_iovec_init_buf(qiov, NULL, 0);
         p = &qiov->local_iov;
@@ -459,6 +471,8 @@ void qemu_iovec_init_extended(
         p->iov_base = tail_buf;
         p->iov_len = tail_len;
     }
+
+    return 0;
 }
 
 /*
@@ -492,7 +506,14 @@ bool qemu_iovec_is_zero(QEMUIOVector *qiov, size_t offset, size_t bytes)
 void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source,
                            size_t offset, size_t len)
 {
-    qemu_iovec_init_extended(qiov, NULL, 0, source, offset, len, NULL, 0);
+    int ret;
+
+    assert(source->size >= len);
+    assert(source->size - len >= offset);
+
+    /* We shrink the request, so we can't overflow neither size_t nor MAX_IOV */
+    ret = qemu_iovec_init_extended(qiov, NULL, 0, source, offset, len, NULL, 0);
+    assert(ret == 0);
 }
 
 void qemu_iovec_destroy(QEMUIOVector *qiov)