Re: [PATCH] smbios: Fix buffer overrun when using path= option

[Thomas Huth]

On 23/03/2025 22.35, Daan De Meyer wrote:
We have to make sure the array of bytes read from the path= file
is null-terminated, otherwise we run into a buffer overrun later on.
Fixes: bb99f4772f54017490e3356ecbb3df25c5d4537f ("hw/smbios: support loading OEM 
strings values from a file")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2879

Signed-off-by: Daan De Meyer <daan.j.deme...@gmail.com>
---
  hw/smbios/smbios.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index 02a09eb9cd..ad4cd6721e 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -1285,6 +1285,9 @@ static int save_opt_one(void *opaque,
              g_byte_array_append(data, (guint8 *)buf, ret);
          }
  
+        buf[0] = '\0';
+        g_byte_array_append(data, (guint8 *)buf, 1);
+
          qemu_close(fd);
  
          *opt->dest = g_renew(char *, *opt->dest, (*opt->ndest) + 1);

Please make sure to put the maintainers on CC: (done now, for the next time 
please see the MAINTAINERS file or use the scripts/get_maintainers.pl 
script), otherwise your patch might go unnoticed.

 Thomas