diff --git a/SOURCES/ping-add-support-for-sub-second-timeouts.patch b/SOURCES/ping-add-support-for-sub-second-timeouts.patch
new file mode 100644
index 0000000..d5ee6b1
--- /dev/null
+++ b/SOURCES/ping-add-support-for-sub-second-timeouts.patch
@@ -0,0 +1,148 @@
+From 1308c7679307e80e638bccce2a6e5eb721fa9d27 Mon Sep 17 00:00:00 2001
+From: Jan Macku <jamacku@redhat.com>
+Date: Wed, 9 Dec 2020 10:23:09 +0100
+Subject: [PATCH] ping: add support for sub-second timeouts
+
+Timeouts (-W) were previously silently rounded down to the next lower
+integral number.  Subsecond values were rounded to zero which resulted in
+infinite timeouts, therefore ping never exited if there were no responses
+and timeouts below 1s.  This commit fixes this issue.
+
+[Sami: I changed ping_strtod() to return double.  Claudius did updated
+needed value by pointer reference, and had multiplication by 1000 in
+wrapper function.  I think that made understanding the code unnecessarily
+difficult, so implementation was slightly changed.]
+
+Backported from upstream PATCH:
+  918e824dc13a39e4d68fcd82fd2d248c9fba6bbd  Claudius Zingerli <gitmail@zeuz.ch>
+  93dfb95d48977d151dbe94983e4998959e748aee  Rosen Penev <rosenp@gmail.com>
+---
+ ping.c | 91 ++++++++++++++++++++++++++++++++++++++--------------------
+ 1 file changed, 60 insertions(+), 31 deletions(-)
+
+diff --git a/ping.c b/ping.c
+index d9a3f5d..fec2453 100644
+--- a/ping.c
++++ b/ping.c
+@@ -57,6 +57,7 @@
+ #ifndef WITHOUT_IFADDRS
+ #include <ifaddrs.h>
+ #endif
++#include <math.h>
+ 
+ #ifndef ICMP_FILTER
+ #define ICMP_FILTER	1
+@@ -192,6 +193,40 @@ static void set_socket_option(socket_st *sock, int level, int optname, const voi
+ 	}
+ }
+ 
++/* Much like stdtod(3, but will fails if str is not valid number. */
++static double ping_strtod(const char *str, const char *err_msg)
++{
++	double num;
++	char *end = NULL;
++
++	if (str == NULL || *str == '\0')
++		goto err;
++	errno = 0;
++#ifdef USE_IDN
++	setlocale(LC_ALL, "C");
++#endif
++	num = strtod(str, &end);
++#ifdef USE_IDN
++	setlocale(LC_ALL, "");
++#endif
++	if (errno || str == end || (end && *end))
++		goto err;
++	switch (fpclassify(num)) {
++	case FP_NORMAL:
++	case FP_ZERO:
++		break;
++	default:
++		errno = ERANGE;
++		goto err;
++	}
++	return num;
++err:
++	if (errno == ERANGE)
++		error(2, errno, "%s: %s", err_msg, str);
++	error(2, 0, "%s: %s", err_msg, str);
++	return num;
++}
++
+ int
+ main(int argc, char **argv)
+ {
+@@ -298,30 +333,19 @@ main(int argc, char **argv)
+ 			options |= F_PTIMEOFDAY;
+ 			break;
+ 		case 'i':
+-		{
+-			double dbl;
+-			char *ep;
+-
+-			errno = 0;
+-#ifdef USE_IDN
+-			setlocale(LC_ALL, "C");
+-#endif
+-			dbl = strtod(optarg, &ep);
+-#ifdef USE_IDN
+-			setlocale(LC_ALL, "");
+-#endif
+-
+-			if (errno || *ep != '\0' ||
+-				!finite(dbl) || dbl < 0.0 || dbl >= (double)INT_MAX / 1000 - 1.0) {
+-				fprintf(stderr, "ping: bad timing interval\n");
+-				exit(2);
+-			}
+-
+-			interval = (int)(dbl * 1000);
+-
+-			options |= F_INTERVAL;
+-			break;
+-		}
++                {
++                        double optval;
++
++                        optval = ping_strtod(optarg, "bad timing interval");
++                        if (isgreater(optval, (double)INT_MAX / 1000)) {
++                                fprintf(stderr, "ping: bad timing interval\n");
++                                exit(2);
++                        }
++
++                        interval = (int)(optval * 1000);
++                        options |= F_INTERVAL;
++                }
++                        break;
+ 		case 'I':
+ 			/* IPv6 */
+ 			if (strchr(optarg, ':')) {
+@@ -460,13 +484,18 @@ main(int argc, char **argv)
+ 			}
+ 			break;
+ 		case 'W':
+-			lingertime = atoi(optarg);
+-			if (lingertime < 0 || lingertime > INT_MAX/1000000) {
+-				fprintf(stderr, "ping: bad linger time.\n");
+-				exit(2);
+-			}
+-			lingertime *= 1000;
+-			break;
++                {
++                        double optval;
++
++                        optval = ping_strtod(optarg, "bad linger time");
++                        if (isless(optval, 0.001) || isgreater(optval, (double)INT_MAX / 1000)) {
++                                fprintf(stderr, "ping: bad linger time.\n");
++                                exit(2);
++                        }
++                        /* lingertime will be converted to usec later */
++                        lingertime = (int)(optval * 1000);
++                }
++                        break;
+ 		default:
+ 			usage();
+ 			break;
+-- 
+2.28.0
+
diff --git a/SPECS/iputils.spec b/SPECS/iputils.spec
index 4bda4ad..43e74f7 100644
--- a/SPECS/iputils.spec
+++ b/SPECS/iputils.spec
@@ -3,7 +3,7 @@
 Summary: Network monitoring tools including ping
 Name: iputils
 Version: 20180629
-Release: 3%{?dist}
+Release: 4%{?dist}
 # some parts are under the original BSD (ping.c)
 # some are under GPLv2+ (tracepath.c)
 License: BSD and GPLv2+
@@ -22,6 +22,7 @@ Patch0: iputils-rh.patch
 Patch1: iputils-ifenslave.patch
 Patch2: iputils-freeaddrinfo.patch
 Patch3: fix-incorrect-statistics.patch
+Patch4: ping-add-support-for-sub-second-timeouts.patch
 
 %if ! 0%{?_module_build}
 BuildRequires: docbook-utils perl-SGMLSpm
@@ -64,6 +65,7 @@ cp %{SOURCE4} %{SOURCE5} .
 %patch1 -p1
 %patch2 -p1
 %patch3 -p1
+%patch4 -p1
 
 %build
 %ifarch s390 s390x
@@ -167,6 +169,9 @@ install -m 644 %SOURCE3 ${RPM_BUILD_ROOT}/%{_unitdir}
 %endif
 
 %changelog
+* Wed Dec 09 2020 Jan Macku <jamacku@redhat.com> - 20180629-4
+- Fix infinite loop caused by subsecond timeouts (#1852638)
+
 * Tue Dec 08 2020 Jan Macku <jamacku@redhat.com> - 20180629-3
 - Fix incorrect ping statistics (#1901780)