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d95d9a31ac
Static analysis on linux-next has detected the following issue
in function virtnet_stats_ctx_init, in drivers/net/virtio_net.c :
if (vi->device_stats_cap & VIRTIO_NET_STATS_TYPE_CVQ) {
queue_type = VIRTNET_Q_TYPE_CQ;
ctx->bitmap[queue_type] |= VIRTIO_NET_STATS_TYPE_CVQ;
ctx->desc_num[queue_type] += ARRAY_SIZE(virtnet_stats_cvq_desc);
ctx->size[queue_type] += sizeof(struct virtio_net_stats_cvq);
}
ctx->bitmap is declared as a u32 however it is being bit-wise or'd with
VIRTIO_NET_STATS_TYPE_CVQ and this is defined as 1 << 32:
include/uapi/linux/virtio_net.h:#define VIRTIO_NET_STATS_TYPE_CVQ (1ULL << 32)
..and hence the bit-wise or operation won't set any bits in ctx->bitmap
because 1ULL < 32 is too wide for a u32.
In fact, the field is read into a u64:
u64 offset, bitmap;
....
bitmap = ctx->bitmap[queue_type];
so to fix, it is enough to make bitmap an array of u64.
Fixes: 941168f8b4 ("virtio_net: support device stats")
Reported-by: "Colin King (gmail)" <colin.i.king@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/53e2bd6728136d5916e384a7840e5dc7eebff832.1729099611.git.mst@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.