fix possible access to uninitialized memory in shgetc (via scanf)

[oweals/musl.git] / src / internal / shgetc.c

diff --git a/src/internal/shgetc.c b/src/internal/shgetc.c
index a4a9c633dc976033622003c3cc7e5068466076bd..7455d2f00a04e477db9f4129fb4d5ba0809af1cb 100644 (file)
--- a/src/internal/shgetc.c
+++ b/src/internal/shgetc.c
@@ -32,6 +32,6 @@ int __shgetc(FILE *f)
        else
                f->shend = f->rend;
        f->shcnt = f->buf - f->rpos + cnt;
-       if (f->rpos[-1] != c) f->rpos[-1] = c;
+       if (f->rpos <= f->buf) f->rpos[-1] = c;
        return c;
 }