From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon, 21 Apr 2025 18:12:21 +0000 (-0300)
Subject: math: Fix UB in setayload
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=beb6d2de65281e86cc643d796f98a9b6045765e3;p=thirdparty%2Fglibc.git

math: Fix UB in setayload

The code can shift the 1ULL for value larger than 63 depending of
the exponent value.  Add a check prior the shift.
---

diff --git a/sysdeps/ieee754/dbl-64/s_setpayload_main.c b/sysdeps/ieee754/dbl-64/s_setpayload_main.c
index 779371837c..2c6c946ae7 100644
--- a/sysdeps/ieee754/dbl-64/s_setpayload_main.c
+++ b/sysdeps/ieee754/dbl-64/s_setpayload_main.c
@@ -37,7 +37,9 @@ FUNC (double *x, double payload)
      except for 0 when allowed; (c) not an integer.  */
   if (exponent >= BIAS + PAYLOAD_DIG
       || (exponent < BIAS && !(SET_HIGH_BIT && ix == 0))
-      || (ix & ((1ULL << (BIAS + EXPLICIT_MANT_DIG - exponent)) - 1)) != 0)
+      || ((BIAS + EXPLICIT_MANT_DIG - exponent) < 64
+	  && (ix & ((1ULL << (BIAS + EXPLICIT_MANT_DIG - exponent)) - 1))
+	  != 0))
     {
       INSERT_WORDS64 (*x, 0);
       return 1;