compat/winansi: check result before using Name field

NtQueryObject can return a success but fill out no name. In those situations, it will set the last argument to the size of the passed in struct, that being 16, to indicate that the name field is NULL. Without this change, using git compiled for Windows under wine in certain circumstances can result in a crash due to a null pointer dereference. Signed-off-by: Christopher Degawa <[email protected]>
git-for-windows · May 28, 2022 · 8a45589 · 8a45589
1 parent 3260e2e
commit 8a45589
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/compat/winansi.c b/compat/winansi.c
@@ -573,6 +573,8 @@ static void detect_msys_tty(int fd)
 	if (!NT_SUCCESS(NtQueryObject(h, ObjectNameInformation,
 			buffer, sizeof(buffer) - 2, &result)))
 		return;
+	if (result <= sizeof(*nameinfo))
+		return;
 	name = nameinfo->Name.Buffer;
 	name[nameinfo->Name.Length / sizeof(*name)] = 0;