Messages in this thread Patch in this message | | | From | Maxime Coquelin <> | Subject | [PATCH] vduse: prevent uninitialized memory accesses | Date | Fri, 26 Aug 2022 18:16:05 +0200 |
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If the VDUSE application provides a smaller config space than the driver expects, the driver may use uninitialized memory from the stack.
This patch prevents it by initializing the buffer passed by the driver to store the config value.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> --- drivers/vdpa/vdpa_user/vduse_dev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 41c0b29739f1..35dceee3ed56 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -673,10 +673,15 @@ static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned int offset, { struct vduse_dev *dev = vdpa_to_vduse(vdpa); - if (offset > dev->config_size || - len > dev->config_size - offset) + /* Initialize the buffer in case of partial copy. */ + memset(buf, 0, len); + + if (offset > dev->config_size) return; + if (len > dev->config_size - offset) + len = dev->config_size - offset; + memcpy(buf, dev->config + offset, len); } -- 2.37.1
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