Package: slirp
Severity: important
Tags: patch upstream
Dear Maintainer,
When trying to use slirp with user-mode-linux (eth0=slirp) under Debian
bookworm (amd64), I noticed that as soon as I up the virtual interface,
slirp prints its usual banner and immediately exits with status 1. The
slirp process started by UML becomes a zombie and there's no network
connectivity. Some debugging led me to believe that the cause is
signedness difference at src/main.c:955 in the
if (timeout.tv_usec == -1) { ... }
comparison, which makes the condition always false, thus reaching the
select() call with timeout.tv_usec (of unsiged type) set to 0xffffffff
(that is -1 converted to unsigned) and thus hitting EINVAL. Adding an
explicit cast via the below patch helped. This problem might affect
64-bit architectures only; I tested on amd64. Please consider fixing
this one way or another.
Thanks,
Feri.
$ cat slirp-1.0.17/debian/patches/018-tv_usec-is-unsigned.patch
Index: slirp-1.0.17/src/main.c
===================================================================
--- slirp-1.0.17.orig/src/main.c 2023-08-07 11:49:03.000000000 +0200
+++ slirp-1.0.17/src/main.c 2023-08-07 11:57:06.850518113 +0200
@@ -859,7 +859,7 @@
* First, see the timeout needed by *timo
*/
timeout.tv_sec = 0;
- timeout.tv_usec = -1;
+ timeout.tv_usec = (unsigned)-1;
/*
* If a slowtimo is needed, set timeout to 500ms from the last
* slow timeout. If a fast timeout is needed, set timeout within
@@ -952,7 +952,7 @@
* This will make timings (like idle timer and "wait" timer)
* up to 10 seconds late, but will be more system friendly
*/
- if (timeout.tv_usec == -1) {
+ if (timeout.tv_usec == (unsigned)-1) {
timeout.tv_usec = 0;
timeout.tv_sec = 5; /* XXX */
}
