target/s390x/arch_dump: Fix memory corruption in s390x_write_elf64_notes()

"note_size" can be smaller than sizeof(note), so unconditionally calling
memset(notep, 0, sizeof(note)) could cause a memory corruption here in
case notep has been allocated dynamically, thus let's use note_size as
length argument for memset() instead.

Reported-by: Sebastian Mitterle <smitterl@redhat.com>
Fixes: 113d8f4e95 ("s390x: pv: Add dump support")
Message-Id: <20230214141056.680969-1-thuth@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

diff --git a/target/s390x/arch_dump.c b/target/s390x/arch_dump.c
index a232914..a7c44ba 100644 (file)
--- a/target/s390x/arch_dump.c
+++ b/target/s390x/arch_dump.c
@@ -248,7 +248,7 @@ static int s390x_write_elf64_notes(const char *note_name,
             notep = g_malloc(note_size);
         }
 
-        memset(notep, 0, sizeof(note));
+        memset(notep, 0, note_size);
 
         /* Setup note header data */
         notep->hdr.n_descsz = cpu_to_be32(content_size);