From: Arnaldo Carvalho de Melo Date: Sat, 13 Jun 2026 17:55:32 +0000 (-0300) Subject: perf cs-etm: Bounds-check CPU in cs_etm__get_queue() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9a989e60cc6e29d98aed2087425cba53bf4b392d;p=thirdparty%2Flinux.git perf cs-etm: Bounds-check CPU in cs_etm__get_queue() cs_etm__get_queue() indexes etm->queues.queue_array[cpu] without validating that cpu is within nr_queues. When processing AUX_OUTPUT_HW_ID events, the cpu value comes from untrusted perf.data trace payload and flows through cs_etm__process_trace_id_v0_1() and cs_etm__queue_aux_fragment() without bounds checking, allowing an out-of-bounds read with a crafted file. Add a bounds check in cs_etm__get_queue() and NULL checks in all callers. Also add NULL checks for queue_array[i].priv in the queue iteration loops in cs_etm__map_trace_id_v0() and cs_etm__process_trace_id_v0_1() — after auxtrace_queues__grow() new entries are zero-initialized so .priv can be NULL. Add a get_cpu_data() NULL check in cs_etm__process_trace_id_v0_1(), matching the existing check in cs_etm__process_trace_id_v0(). Fixes: 77c123f53e97ad4b ("perf: cs-etm: Move traceid_list to each queue") Reported-by: sashiko-bot Cc: Adrian Hunter Cc: James Clark Cc: Leo Yan Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index d121c8f22028d..5d0664ff73b79 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -292,8 +292,11 @@ static struct cs_etm_queue *cs_etm__get_queue(struct cs_etm_auxtrace *etm, int c { if (etm->per_thread_decoding) return etm->queues.queue_array[0].priv; - else - return etm->queues.queue_array[cpu].priv; + + if (cpu < 0 || cpu >= (int)etm->queues.nr_queues) + return NULL; + + return etm->queues.queue_array[cpu].priv; } static int cs_etm__map_trace_id_v0(struct cs_etm_auxtrace *etm, u8 trace_chan_id, @@ -306,6 +309,9 @@ static int cs_etm__map_trace_id_v0(struct cs_etm_auxtrace *etm, u8 trace_chan_id * queue associated with that CPU so only one decoder is made. */ etmq = cs_etm__get_queue(etm, cpu_metadata[CS_ETM_CPU]); + if (!etmq) + return -EINVAL; + if (etmq->format == UNFORMATTED) return cs_etm__insert_trace_id_node(etmq, trace_chan_id, cpu_metadata); @@ -318,6 +324,9 @@ static int cs_etm__map_trace_id_v0(struct cs_etm_auxtrace *etm, u8 trace_chan_id int ret; etmq = etm->queues.queue_array[i].priv; + if (!etmq) + continue; + ret = cs_etm__insert_trace_id_node(etmq, trace_chan_id, cpu_metadata); if (ret) @@ -358,6 +367,9 @@ static int cs_etm__process_trace_id_v0_1(struct cs_etm_auxtrace *etm, int cpu, u32 sink_id = FIELD_GET(CS_AUX_HW_ID_SINK_ID_MASK, hw_id); u8 trace_id = FIELD_GET(CS_AUX_HW_ID_TRACE_ID_MASK, hw_id); + if (!etmq) + return -EINVAL; + /* * Check sink id hasn't changed in per-cpu mode. In per-thread mode, * let it pass for now until an actual overlapping trace ID is hit. In @@ -375,6 +387,9 @@ static int cs_etm__process_trace_id_v0_1(struct cs_etm_auxtrace *etm, int cpu, for (unsigned int i = 0; i < etm->queues.nr_queues; ++i) { struct cs_etm_queue *other_etmq = etm->queues.queue_array[i].priv; + if (!other_etmq) + continue; + /* Different sinks, skip */ if (other_etmq->sink_id != etmq->sink_id) continue; @@ -396,6 +411,9 @@ static int cs_etm__process_trace_id_v0_1(struct cs_etm_auxtrace *etm, int cpu, } cpu_data = get_cpu_data(etm, cpu); + if (!cpu_data) + return -EINVAL; + ret = cs_etm__insert_trace_id_node(etmq, trace_id, cpu_data); if (ret) return ret; @@ -3144,6 +3162,9 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o aux_offset + aux_size <= auxtrace_event->offset + auxtrace_event->size) { struct cs_etm_queue *etmq = cs_etm__get_queue(etm, auxtrace_event->cpu); + if (!etmq) + return -EINVAL; + /* * If this AUX event was inside this buffer somewhere, create a new auxtrace event * based on the sizes of the aux event, and queue that fragment.