From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com,
berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com,
stefanha@redhat.com, den@openvz.org
Subject: [PATCH v4 02/16] util/iov: make qemu_iovec_init_extended() honest
Date: Fri, 11 Dec 2020 21:39:20 +0300 [thread overview]
Message-ID: <20201211183934.169161-3-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20201211183934.169161-1-vsementsov@virtuozzo.com>
Actually, we can't extend the io vector in all cases. Handle possible
MAX_IOV and size_t overflows.
For now add assertion to callers (actually they rely on success anyway)
and fix them in the following patch.
Add also some additional good assertions to qemu_iovec_init_slice()
while being here.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
include/qemu/iov.h | 2 +-
block/io.c | 10 +++++++---
util/iov.c | 25 +++++++++++++++++++++++--
3 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index b6b283a5e5..9330746680 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -222,7 +222,7 @@ static inline void *qemu_iovec_buf(QEMUIOVector *qiov)
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint);
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
-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,
diff --git a/block/io.c b/block/io.c
index e076236db2..21e8a50725 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1652,13 +1652,17 @@ static bool bdrv_pad_request(BlockDriverState *bs,
int64_t *offset, unsigned int *bytes,
BdrvRequestPadding *pad)
{
+ int ret;
+
if (!bdrv_init_padding(bs, *offset, *bytes, pad)) {
return false;
}
- qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
- *qiov, *qiov_offset, *bytes,
- pad->buf + pad->buf_len - pad->tail, pad->tail);
+ ret = qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
+ *qiov, *qiov_offset, *bytes,
+ pad->buf + pad->buf_len - pad->tail,
+ pad->tail);
+ assert(ret == 0);
*bytes += pad->head + pad->tail;
*offset -= pad->head;
*qiov = &pad->local_qiov;
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)
--
2.25.4
next prev parent reply other threads:[~2020-12-11 18:51 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-11 18:39 [PATCH v4 00/16] 64bit block-layer: part I Vladimir Sementsov-Ogievskiy
2020-12-11 18:39 ` [PATCH v4 01/16] block: refactor bdrv_check_request: add errp Vladimir Sementsov-Ogievskiy
2021-01-20 22:20 ` Eric Blake
2021-01-22 19:33 ` Eric Blake
2020-12-11 18:39 ` Vladimir Sementsov-Ogievskiy [this message]
2021-01-21 21:58 ` [PATCH v4 02/16] util/iov: make qemu_iovec_init_extended() honest Eric Blake
2020-12-11 18:39 ` [PATCH v4 03/16] block: fix theoretical overflow in bdrv_init_padding() Vladimir Sementsov-Ogievskiy
2021-01-21 22:42 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 04/16] block/io: refactor bdrv_pad_request(): move bdrv_pad_request() up Vladimir Sementsov-Ogievskiy
2021-01-21 22:50 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 05/16] block/io: bdrv_pad_request(): support qemu_iovec_init_extended failure Vladimir Sementsov-Ogievskiy
2021-01-21 22:53 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 06/16] block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes Vladimir Sementsov-Ogievskiy
2020-12-11 18:39 ` [PATCH v4 07/16] block/io: improve bdrv_check_request: check qiov too Vladimir Sementsov-Ogievskiy
2021-01-22 14:48 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 08/16] block: use int64_t as bytes type in tracked requests Vladimir Sementsov-Ogievskiy
2021-01-22 14:50 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 09/16] block/io: use int64_t bytes in driver wrappers Vladimir Sementsov-Ogievskiy
2021-01-22 16:02 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 10/16] block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes() Vladimir Sementsov-Ogievskiy
2021-01-22 16:18 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 11/16] block/io: support int64_t bytes in bdrv_aligned_pwritev() Vladimir Sementsov-Ogievskiy
2021-01-22 16:26 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 12/16] block/io: support int64_t bytes in bdrv_co_do_copy_on_readv() Vladimir Sementsov-Ogievskiy
2021-01-22 16:34 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 13/16] block/io: support int64_t bytes in bdrv_aligned_preadv() Vladimir Sementsov-Ogievskiy
2021-01-22 16:54 ` Eric Blake
2021-01-23 14:34 ` Vladimir Sementsov-Ogievskiy
2020-12-11 18:39 ` [PATCH v4 14/16] block/io: support int64_t bytes in bdrv_co_p{read, write}v_part() Vladimir Sementsov-Ogievskiy via
2021-01-22 17:00 ` [PATCH v4 14/16] block/io: support int64_t bytes in bdrv_co_p{read,write}v_part() Eric Blake
2020-12-11 18:39 ` [PATCH v4 15/16] block/io: support int64_t bytes in read/write wrappers Vladimir Sementsov-Ogievskiy
2021-01-22 17:22 ` Eric Blake
2020-12-11 18:39 ` [PATCH v4 16/16] block/io: use int64_t bytes in copy_range Vladimir Sementsov-Ogievskiy
2021-01-22 18:29 ` Eric Blake
2020-12-14 11:51 ` [PATCH v4 00/16] 64bit block-layer: part I Vladimir Sementsov-Ogievskiy
2021-01-09 10:13 ` Vladimir Sementsov-Ogievskiy
2021-02-02 2:56 ` Eric Blake
2021-02-02 6:50 ` Vladimir Sementsov-Ogievskiy
2021-02-02 14:59 ` Eric Blake
2021-02-02 16:13 ` iotest failures in head [was: [PATCH v4 00/16] 64bit block-layer: part I] Eric Blake
2021-02-02 16:23 ` Kevin Wolf
2021-02-02 16:29 ` Vladimir Sementsov-Ogievskiy
2021-02-02 18:50 ` Vladimir Sementsov-Ogievskiy
2021-02-02 22:47 ` Peter Maydell
2021-02-03 10:45 ` Peter Maydell
2021-02-04 15:18 ` Peter Maydell
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