From 8e3a67f2de87ee94ac11ea69beb4edc2993b17a0 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Sat, 10 Aug 2024 14:20:57 +0800
Subject: crypto: lib/mpi - Add error checks to extension

The remaining functions added by commit
a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e did not check for memory
allocation errors.  Add the checks and change the API to allow errors
to be returned.

Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 lib/crypto/mpi/mpi-mul.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

(limited to 'lib/crypto/mpi/mpi-mul.c')

diff --git a/lib/crypto/mpi/mpi-mul.c b/lib/crypto/mpi/mpi-mul.c
index 7f4eda8560dc..892a246216b9 100644
--- a/lib/crypto/mpi/mpi-mul.c
+++ b/lib/crypto/mpi/mpi-mul.c
@@ -13,7 +13,7 @@
 
 #include "mpi-internal.h"
 
-void mpi_mul(MPI w, MPI u, MPI v)
+int mpi_mul(MPI w, MPI u, MPI v)
 {
 	mpi_size_t usize, vsize, wsize;
 	mpi_ptr_t up, vp, wp;
@@ -21,6 +21,7 @@ void mpi_mul(MPI w, MPI u, MPI v)
 	int usign, vsign, sign_product;
 	int assign_wp = 0;
 	mpi_ptr_t tmp_limb = NULL;
+	int err;
 
 	if (u->nlimbs < v->nlimbs) {
 		/* Swap U and V. */
@@ -46,15 +47,21 @@ void mpi_mul(MPI w, MPI u, MPI v)
 	if (w->alloced < wsize) {
 		if (wp == up || wp == vp) {
 			wp = mpi_alloc_limb_space(wsize);
+			if (!wp)
+				return -ENOMEM;
 			assign_wp = 1;
 		} else {
-			mpi_resize(w, wsize);
+			err = mpi_resize(w, wsize);
+			if (err)
+				return err;
 			wp = w->d;
 		}
 	} else { /* Make U and V not overlap with W.	*/
 		if (wp == up) {
 			/* W and U are identical.  Allocate temporary space for U. */
 			up = tmp_limb = mpi_alloc_limb_space(usize);
+			if (!up)
+				return -ENOMEM;
 			/* Is V identical too?  Keep it identical with U.  */
 			if (wp == vp)
 				vp = up;
@@ -63,6 +70,8 @@ void mpi_mul(MPI w, MPI u, MPI v)
 		} else if (wp == vp) {
 			/* W and V are identical.  Allocate temporary space for V. */
 			vp = tmp_limb = mpi_alloc_limb_space(vsize);
+			if (!vp)
+				return -ENOMEM;
 			/* Copy to the temporary space.  */
 			MPN_COPY(vp, wp, vsize);
 		}
@@ -71,7 +80,12 @@ void mpi_mul(MPI w, MPI u, MPI v)
 	if (!vsize)
 		wsize = 0;
 	else {
-		mpihelp_mul(wp, up, usize, vp, vsize, &cy);
+		err = mpihelp_mul(wp, up, usize, vp, vsize, &cy);
+		if (err) {
+			if (assign_wp)
+				mpi_free_limb_space(wp);
+			goto free_tmp_limb;
+		}
 		wsize -= cy ? 0:1;
 	}
 
@@ -79,14 +93,17 @@ void mpi_mul(MPI w, MPI u, MPI v)
 		mpi_assign_limb_space(w, wp, wsize);
 	w->nlimbs = wsize;
 	w->sign = sign_product;
+
+free_tmp_limb:
 	if (tmp_limb)
 		mpi_free_limb_space(tmp_limb);
+	return err;
 }
 EXPORT_SYMBOL_GPL(mpi_mul);
 
-void mpi_mulm(MPI w, MPI u, MPI v, MPI m)
+int mpi_mulm(MPI w, MPI u, MPI v, MPI m)
 {
-	mpi_mul(w, u, v);
-	mpi_tdiv_r(w, w, m);
+	return mpi_mul(w, u, v) ?:
+	       mpi_tdiv_r(w, w, m);
 }
 EXPORT_SYMBOL_GPL(mpi_mulm);
-- 
cgit