This is a note to let you know that I've just added the patch titled
virtio_blk: fix snprintf truncation compiler warning
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio_blk-fix-snprintf-truncation-compiler-warning.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 59edd3111eadddeb6716482e89b51b36746078e1
Author: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Date: Mon Dec 4 09:07:43 2023 -0500
virtio_blk: fix snprintf truncation compiler warning
[ Upstream commit b8e0792449928943c15d1af9f63816911d139267 ]
Commit 4e0400525691 ("virtio-blk: support polling I/O") triggers the
following gcc 13 W=1 warnings:
drivers/block/virtio_blk.c: In function ‘init_vq’:
drivers/block/virtio_blk.c:1077:68: warning: ‘%d’ directive output may be truncated writing between 1 and 11 bytes into a region of size 7 [-Wformat-truncation=]
1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~
drivers/block/virtio_blk.c:1077:58: note: directive argument in the range [-2147483648, 65534]
1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~~~~~~~~~~~~
drivers/block/virtio_blk.c:1077:17: note: ‘snprintf’ output between 11 and 21 bytes into a destination of size 16
1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is a false positive because the lower bound -2147483648 is
incorrect. The true range of i is [0, num_vqs - 1] where 0 < num_vqs <
65536.
The code mixes int, unsigned short, and unsigned int types in addition
to using "%d" for an unsigned value. Use unsigned short and "%u"
consistently to solve the compiler warning.
Cc: Suwan Kim <suwan.kim027@xxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202312041509.DIyvEt9h-lkp@xxxxxxxxx/
Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Message-Id: <20231204140743.1487843-1-stefanha@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 4a4b9bad551e..225c86c74d4e 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -1021,12 +1021,12 @@ static void virtblk_config_changed(struct virtio_device *vdev)
static int init_vq(struct virtio_blk *vblk)
{
int err;
- int i;
+ unsigned short i;
vq_callback_t **callbacks;
const char **names;
struct virtqueue **vqs;
unsigned short num_vqs;
- unsigned int num_poll_vqs;
+ unsigned short num_poll_vqs;
struct virtio_device *vdev = vblk->vdev;
struct irq_affinity desc = { 0, };
@@ -1070,13 +1070,13 @@ static int init_vq(struct virtio_blk *vblk)
for (i = 0; i < num_vqs - num_poll_vqs; i++) {
callbacks[i] = virtblk_done;
- snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
+ snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i);
names[i] = vblk->vqs[i].name;
}
for (; i < num_vqs; i++) {
callbacks[i] = NULL;
- snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i);
+ snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i);
names[i] = vblk->vqs[i].name;
}
