Messages in this thread | | | Date | Wed, 23 Jan 2013 23:26:20 +0000 | From | Colin Ian King <> | Subject | Re: [PATCH] perf evsel: fix NULL pointer deference when evsel->counts is NULL |
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On 23/01/13 22:02, Arnaldo Carvalho de Melo wrote: > Em Mon, Jan 21, 2013 at 01:53:21PM +0900, Namhyung Kim escreveu: >> On Sat, 19 Jan 2013 16:36:54 +0000, Colin King wrote: >>> From: Colin Ian King <colin.king@canonical.com> > >>> __perf_evsel__read_on_cpu() only bails out with -ENOMEM if >>> evsel->counts is NULL and perf_evsel__alloc_counts() has returned >>> an error. If perf_evsel__alloc_counts() does not return an error >>> we get an NULL pointer deference on evsel->counts->cpu[cpu] >>> if evsel->counts is NULL. > >> perf_evsel__alloc_counts() should allocate evsel->counts when it sees >> evsel->counts is NULL and return negative error code if the allocation >> fails. > >> So I don't see any problem in current code. With your code, it won't >> try to allocate if ->counts is NULL but overwrite existing ->counts? > > Right, the patch introduces a problem in code that works perfectly :-) > > - Arnaldo > Apologies for the noise.
Colin
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