1 files changed, 34 insertions, 80 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index cf2eb07ddf28..0126c9c80c58 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -12726,36 +12726,6 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 	return 0;
 }
 
-static bool signed_add_overflows(s64 a, s64 b)
-{
-	/* Do the add in u64, where overflow is well-defined */
-	s64 res = (s64)((u64)a + (u64)b);
-
-	if (b < 0)
-		return res > a;
-	return res < a;
-}
-
-static bool signed_add32_overflows(s32 a, s32 b)
-{
-	/* Do the add in u32, where overflow is well-defined */
-	s32 res = (s32)((u32)a + (u32)b);
-
-	if (b < 0)
-		return res > a;
-	return res < a;
-}
-
-static bool signed_add16_overflows(s16 a, s16 b)
-{
-	/* Do the add in u16, where overflow is well-defined */
-	s16 res = (s16)((u16)a + (u16)b);
-
-	if (b < 0)
-		return res > a;
-	return res < a;
-}
-
 static bool signed_sub_overflows(s64 a, s64 b)
 {
 	/* Do the sub in u64, where overflow is well-defined */
@@ -13257,21 +13227,15 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 		 * added into the variable offset, and we copy the fixed offset
 		 * from ptr_reg.
 		 */
-		if (signed_add_overflows(smin_ptr, smin_val) ||
-		    signed_add_overflows(smax_ptr, smax_val)) {
+		if (check_add_overflow(smin_ptr, smin_val, &dst_reg->smin_value) ||
+		    check_add_overflow(smax_ptr, smax_val, &dst_reg->smax_value)) {
 			dst_reg->smin_value = S64_MIN;
 			dst_reg->smax_value = S64_MAX;
-		} else {
-			dst_reg->smin_value = smin_ptr + smin_val;
-			dst_reg->smax_value = smax_ptr + smax_val;
 		}
-		if (umin_ptr + umin_val < umin_ptr ||
-		    umax_ptr + umax_val < umax_ptr) {
+		if (check_add_overflow(umin_ptr, umin_val, &dst_reg->umin_value) ||
+		    check_add_overflow(umax_ptr, umax_val, &dst_reg->umax_value)) {
 			dst_reg->umin_value = 0;
 			dst_reg->umax_value = U64_MAX;
-		} else {
-			dst_reg->umin_value = umin_ptr + umin_val;
-			dst_reg->umax_value = umax_ptr + umax_val;
 		}
 		dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off);
 		dst_reg->off = ptr_reg->off;
@@ -13374,52 +13338,40 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 static void scalar32_min_max_add(struct bpf_reg_state *dst_reg,
 				 struct bpf_reg_state *src_reg)
 {
-	s32 smin_val = src_reg->s32_min_value;
-	s32 smax_val = src_reg->s32_max_value;
-	u32 umin_val = src_reg->u32_min_value;
-	u32 umax_val = src_reg->u32_max_value;
+	s32 *dst_smin = &dst_reg->s32_min_value;
+	s32 *dst_smax = &dst_reg->s32_max_value;
+	u32 *dst_umin = &dst_reg->u32_min_value;
+	u32 *dst_umax = &dst_reg->u32_max_value;
 
-	if (signed_add32_overflows(dst_reg->s32_min_value, smin_val) ||
-	    signed_add32_overflows(dst_reg->s32_max_value, smax_val)) {
-		dst_reg->s32_min_value = S32_MIN;
-		dst_reg->s32_max_value = S32_MAX;
-	} else {
-		dst_reg->s32_min_value += smin_val;
-		dst_reg->s32_max_value += smax_val;
+	if (check_add_overflow(*dst_smin, src_reg->s32_min_value, dst_smin) ||
+	    check_add_overflow(*dst_smax, src_reg->s32_max_value, dst_smax)) {
+		*dst_smin = S32_MIN;
+		*dst_smax = S32_MAX;
 	}
-	if (dst_reg->u32_min_value + umin_val < umin_val ||
-	    dst_reg->u32_max_value + umax_val < umax_val) {
-		dst_reg->u32_min_value = 0;
-		dst_reg->u32_max_value = U32_MAX;
-	} else {
-		dst_reg->u32_min_value += umin_val;
-		dst_reg->u32_max_value += umax_val;
+	if (check_add_overflow(*dst_umin, src_reg->u32_min_value, dst_umin) ||
+	    check_add_overflow(*dst_umax, src_reg->u32_max_value, dst_umax)) {
+		*dst_umin = 0;
+		*dst_umax = U32_MAX;
 	}
 }
 
 static void scalar_min_max_add(struct bpf_reg_state *dst_reg,
 			       struct bpf_reg_state *src_reg)
 {
-	s64 smin_val = src_reg->smin_value;
-	s64 smax_val = src_reg->smax_value;
-	u64 umin_val = src_reg->umin_value;
-	u64 umax_val = src_reg->umax_value;
+	s64 *dst_smin = &dst_reg->smin_value;
+	s64 *dst_smax = &dst_reg->smax_value;
+	u64 *dst_umin = &dst_reg->umin_value;
+	u64 *dst_umax = &dst_reg->umax_value;
 
-	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
-	    signed_add_overflows(dst_reg->smax_value, smax_val)) {
-		dst_reg->smin_value = S64_MIN;
-		dst_reg->smax_value = S64_MAX;
-	} else {
-		dst_reg->smin_value += smin_val;
-		dst_reg->smax_value += smax_val;
+	if (check_add_overflow(*dst_smin, src_reg->smin_value, dst_smin) ||
+	    check_add_overflow(*dst_smax, src_reg->smax_value, dst_smax)) {
+		*dst_smin = S64_MIN;
+		*dst_smax = S64_MAX;
 	}
-	if (dst_reg->umin_value + umin_val < umin_val ||
-	    dst_reg->umax_value + umax_val < umax_val) {
-		dst_reg->umin_value = 0;
-		dst_reg->umax_value = U64_MAX;
-	} else {
-		dst_reg->umin_value += umin_val;
-		dst_reg->umax_value += umax_val;
+	if (check_add_overflow(*dst_umin, src_reg->umin_value, dst_umin) ||
+	    check_add_overflow(*dst_umax, src_reg->umax_value, dst_umax)) {
+		*dst_umin = 0;
+		*dst_umax = U64_MAX;
 	}
 }
 
@@ -18835,6 +18787,8 @@ static int adjust_jmp_off(struct bpf_prog *prog, u32 tgt_idx, u32 delta)
 {
 	struct bpf_insn *insn = prog->insnsi;
 	u32 insn_cnt = prog->len, i;
+	s32 imm;
+	s16 off;
 
 	for (i = 0; i < insn_cnt; i++, insn++) {
 		u8 code = insn->code;
@@ -18846,15 +18800,15 @@ static int adjust_jmp_off(struct bpf_prog *prog, u32 tgt_idx, u32 delta)
 		if (insn->code == (BPF_JMP32 | BPF_JA)) {
 			if (i + 1 + insn->imm != tgt_idx)
 				continue;
-			if (signed_add32_overflows(insn->imm, delta))
+			if (check_add_overflow(insn->imm, delta, &imm))
 				return -ERANGE;
-			insn->imm += delta;
+			insn->imm = imm;
 		} else {
 			if (i + 1 + insn->off != tgt_idx)
 				continue;
-			if (signed_add16_overflows(insn->off, delta))
+			if (check_add_overflow(insn->off, delta, &off))
 				return -ERANGE;
-			insn->off += delta;
+			insn->off = off;
 		}
 	}
 	return 0;