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author | Simon Kelley <simon@thekelleys.org.uk> | 2021-10-06 22:31:06 +0100 |
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committer | Simon Kelley <simon@thekelleys.org.uk> | 2021-10-06 22:31:06 +0100 |
commit | d290630d31f4517ab26392d00753d1397f9a4114 (patch) | |
tree | 606097cbc0adc753dddfb2461a2469cfb9f232a1 | |
parent | d2ad5dc073aaacaf22b117f16106282a73586803 (diff) | |
download | dnsmasq-d290630d31f4517ab26392d00753d1397f9a4114.tar.gz |
Fix crash after re-reading an empty resolv.conf file.
If dnsmasq re-reads a resolv file, and it's empty, it will
retry after a delay. In the meantime, the old servers from the
resolv file have been deleted, but the servers_array doesn't
get updated, leading to dangling pointers and crashes.
Thanks to Brad Jorsch for finding and analysing this bug.
This problem was introduced in 2.86.
-rw-r--r-- | src/dnsmasq.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/dnsmasq.c b/src/dnsmasq.c index c7fa024..9516680 100644 --- a/src/dnsmasq.c +++ b/src/dnsmasq.c @@ -1682,6 +1682,11 @@ static void poll_resolv(int force, int do_reload, time_t now) } else { + /* If we're delaying things, we don't call check_servers(), but + reload_servers() may have deleted some servers, rendering the server_array + invalid, so just rebuild that here. Once reload_servers() succeeds, + we call check_servers() above, which calls build_server_array itself. */ + build_server_array(); latest->mtime = 0; if (!warned) { |