Re: [PATCH 2/2] hw/rdma: avoid suspicious strncpy() use

[Marcel Apfelbaum]

Hi Stefan,

On 3/20/20 1:55 PM, Yuval Shaia wrote:
> On Mon, 16 Mar 2020 at 18:07, Stefan Hajnoczi <address@hidden 
> <mailto:address@hidden>> wrote:
>
>     gcc (GCC) 9.2.1 20190827 (Red Hat 9.2.1-1) with sanitizers enabled
>     reports the following error:
>
>       CC      x86_64-softmmu/hw/rdma/vmw/pvrdma_dev_ring.o
>     In file included from /usr/include/string.h:495,
>                      from include/qemu/osdep.h:101,
>                      from hw/rdma/vmw/pvrdma_dev_ring.c:16:
>     In function ‘strncpy’,
>         inlined from ‘pvrdma_ring_init’ at
>     hw/rdma/vmw/pvrdma_dev_ring.c:33:5:
>     /usr/include/bits/string_fortified.h:106:10: error:
>     ‘__builtin_strncpy’ specified bound 32 equals destination size
>     [-Werror=stringop-truncation]
>       106 |   return __builtin___strncpy_chk (__dest, __src, __len,
>     __bos (__dest));
>           | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>     Use pstrcpy() instead of strncpy().  It is guaranteed to NUL-terminate
>     strings.
>
>     Signed-off-by: Stefan Hajnoczi <address@hidden
>     <mailto:address@hidden>>
>     ---
>      hw/rdma/vmw/pvrdma_dev_ring.c | 4 ++--
>      1 file changed, 2 insertions(+), 2 deletions(-)
>
>     diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c
>     b/hw/rdma/vmw/pvrdma_dev_ring.c
>     index d7bc7f5ccc..74b8fa834c 100644
>     --- a/hw/rdma/vmw/pvrdma_dev_ring.c
>     +++ b/hw/rdma/vmw/pvrdma_dev_ring.c
>     @@ -14,6 +14,7 @@
>       */
>
>      #include "qemu/osdep.h"
>     +#include "qemu/cutils.h"
>      #include "hw/pci/pci.h"
>      #include "cpu.h"
>
>     @@ -30,8 +31,7 @@ int pvrdma_ring_init(PvrdmaRing *ring, const
>     char *name, PCIDevice *dev,
>          int i;
>          int rc = 0;
>
>     -    strncpy(ring->name, name, MAX_RING_NAME_SZ);
>     -    ring->name[MAX_RING_NAME_SZ - 1] = 0;
>     +    pstrcpy(ring->name, MAX_RING_NAME_SZ, name);
>          ring->dev = dev;
>          ring->ring_state = ring_state;
>          ring->max_elems = max_elems;
>     -- 
>     2.24.1
>
>
> Thanks,
>
> Reviewed-by: Yuval Shaia <yuval.shaia.ml.gmail.com 
> <http://yuval.shaia.ml.gmail.com>>

I'll add this patch to the pvrdma queue.

Thanks,
Marcel