From aa1530dec499f7525d2ccaa0e3a876dc8089ed1e Mon Sep 17 00:00:00 2001 From: Eduardo Otubo Date: Fri, 29 Sep 2017 14:03:39 +0200 Subject: [PATCH] filter-mirror: segfault when specifying non existent device When using filter-mirror like the example below where the interface 'ndev0' does not exist on the host, QEMU crashes into segmentation fault. $ qemu-system-x86_64 -S -machine pc -netdev user,id=ndev0 -object filter-mirror,id=test-object,netdev=ndev0 This happens because the function filter_mirror_setup() does not check if the device actually exists and still keep on processing calling qemu_chr_find(). This patch fixes this issue. Signed-off-by: Eduardo Otubo Signed-off-by: Michael Tokarev --- net/filter-mirror.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/filter-mirror.c b/net/filter-mirror.c index 90e2c92337..ce0dc23c2a 100644 --- a/net/filter-mirror.c +++ b/net/filter-mirror.c @@ -213,6 +213,12 @@ static void filter_mirror_setup(NetFilterState *nf, Error **errp) MirrorState *s = FILTER_MIRROR(nf); Chardev *chr; + if (s->outdev == NULL) { + error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, "filter-mirror parameter"\ + " 'outdev' cannot be empty"); + return; + } + chr = qemu_chr_find(s->outdev); if (chr == NULL) { error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,