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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2015-01-27 21:59:40 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2015-01-27 21:59:40 +0100 |
| commit | 936c401077cc68d9e3dd7f1b0b293ee03ce02bf5 (patch) | |
| tree | 5315bc6e3d1e77602dc4b5f198697e9c49370470 | |
| parent | 64b744997ef399809dc4c78ec45ddfbebde3e597 (diff) | |
| download | busybox-936c401077cc68d9e3dd7f1b0b293ee03ce02bf5.tar.gz | |
dhcpd: fix an improper widening conversion
We wanted to detect when tv_sec = unsigned1 - unsigned2
underflows by looking at tv_sec's sign. But if tv_sec
is long and it is wider than unsigned, we get unsigned -> long
conversion which is in this case never negative.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | networking/udhcp/dhcpd.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c index 4b3ed240c..2de074f9b 100644 --- a/networking/udhcp/dhcpd.c +++ b/networking/udhcp/dhcpd.c @@ -413,7 +413,8 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv) max_sock = udhcp_sp_fd_set(&rfds, server_socket); if (server_config.auto_time) { - tv.tv_sec = timeout_end - monotonic_sec(); + /* cast to signed is essential if tv_sec is wider than int */ + tv.tv_sec = (int)(timeout_end - monotonic_sec()); tv.tv_usec = 0; } retval = 0; |