Messages in this thread |  | | Subject | Re: [PATCH] net: sched: fix a error path in fw_change() | From | liqiong <> | Date | Mon, 5 Dec 2022 10:36:00 +0800 |
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在 2022年12月04日 03:46, Cong Wang 写道: > On Thu, Dec 01, 2022 at 11:15:32PM +0800, Li Qiong wrote: >> The 'pfp' pointer could be null if can't find the target filter. >> Check 'pfp' pointer and fix this error path. > Did you see any actual kernel crash? And do you have a reproducer too? > Please include them if you do. Found this by 'smatch' tool, I check and find it may be a real problem at the risk of NULL pointer. Like 'fw_delete()', It checks 'pfp' and 'pfp == f' too.
> >> Signed-off-by: Li Qiong <liqiong@nfschina.com> >> --- >> net/sched/cls_fw.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c >> index a32351da968c..b898e4a81146 100644 >> --- a/net/sched/cls_fw.c >> +++ b/net/sched/cls_fw.c >> @@ -289,6 +289,12 @@ static int fw_change(struct net *net, struct sk_buff *in_skb, >> if (pfp == f) >> break; >> >> + if (!pfp) { >> + tcf_exts_destroy(&fnew->exts); >> + kfree(fnew); >> + return err; > > BTW, err is 0 here, you have to set some error here. You are right, It should return '-EINVAL' -- can't get the target filter.
> > Thanks.
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