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-bit.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

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

diff --git a/lib/crypto/mpi/mpi-bit.c b/lib/crypto/mpi/mpi-bit.c
index c29b85362664..835a2f0622a0 100644
--- a/lib/crypto/mpi/mpi-bit.c
+++ b/lib/crypto/mpi/mpi-bit.c
@@ -76,9 +76,10 @@ EXPORT_SYMBOL_GPL(mpi_test_bit);
 /****************
  * Set bit N of A.
  */
-void mpi_set_bit(MPI a, unsigned int n)
+int mpi_set_bit(MPI a, unsigned int n)
 {
 	unsigned int i, limbno, bitno;
+	int err;
 
 	limbno = n / BITS_PER_MPI_LIMB;
 	bitno  = n % BITS_PER_MPI_LIMB;
@@ -86,27 +87,31 @@ void mpi_set_bit(MPI a, unsigned int n)
 	if (limbno >= a->nlimbs) {
 		for (i = a->nlimbs; i < a->alloced; i++)
 			a->d[i] = 0;
-		mpi_resize(a, limbno+1);
+		err = mpi_resize(a, limbno+1);
+		if (err)
+			return err;
 		a->nlimbs = limbno+1;
 	}
 	a->d[limbno] |= (A_LIMB_1<<bitno);
+	return 0;
 }
 
 /*
  * Shift A by N bits to the right.
  */
-void mpi_rshift(MPI x, MPI a, unsigned int n)
+int mpi_rshift(MPI x, MPI a, unsigned int n)
 {
 	mpi_size_t xsize;
 	unsigned int i;
 	unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
 	unsigned int nbits = (n%BITS_PER_MPI_LIMB);
+	int err;
 
 	if (x == a) {
 		/* In-place operation.  */
 		if (nlimbs >= x->nlimbs) {
 			x->nlimbs = 0;
-			return;
+			return 0;
 		}
 
 		if (nlimbs) {
@@ -121,7 +126,9 @@ void mpi_rshift(MPI x, MPI a, unsigned int n)
 		/* Copy and shift by more or equal bits than in a limb. */
 		xsize = a->nlimbs;
 		x->sign = a->sign;
-		RESIZE_IF_NEEDED(x, xsize);
+		err = RESIZE_IF_NEEDED(x, xsize);
+		if (err)
+			return err;
 		x->nlimbs = xsize;
 		for (i = 0; i < a->nlimbs; i++)
 			x->d[i] = a->d[i];
@@ -129,7 +136,7 @@ void mpi_rshift(MPI x, MPI a, unsigned int n)
 
 		if (nlimbs >= x->nlimbs) {
 			x->nlimbs = 0;
-			return;
+			return 0;
 		}
 
 		for (i = 0; i < x->nlimbs - nlimbs; i++)
@@ -143,7 +150,9 @@ void mpi_rshift(MPI x, MPI a, unsigned int n)
 		/* Copy and shift by less than bits in a limb.  */
 		xsize = a->nlimbs;
 		x->sign = a->sign;
-		RESIZE_IF_NEEDED(x, xsize);
+		err = RESIZE_IF_NEEDED(x, xsize);
+		if (err)
+			return err;
 		x->nlimbs = xsize;
 
 		if (xsize) {
@@ -159,5 +168,7 @@ void mpi_rshift(MPI x, MPI a, unsigned int n)
 		}
 	}
 	MPN_NORMALIZE(x->d, x->nlimbs);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mpi_rshift);
-- 
cgit