mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 01:08:13 -04:00
Code Issues Packages Projects Releases Wiki Activity

perf tools: Guard test_bit from out-of-bounds sample CPU

Browse Source 
When PERF_SAMPLE_CPU is absent from a perf.data file, sample->cpu is
initialized to (u32)-1 by evsel__parse_sample().  Five call sites pass
this value directly to test_bit(sample->cpu, cpu_bitmap), reading
massively out of bounds past the DECLARE_BITMAP(..., MAX_NR_CPUS)
allocation of 4096 bits.

Add a sample->cpu >= MAX_NR_CPUS guard before each test_bit() call,
matching the existing safe pattern in builtin-kwork.c.  This catches
both the (u32)-1 sentinel and any corrupted CPU value exceeding the
bitmap size.

Fixes: 5d67be97f8 ("perf report/annotate/script: Add option to specify a CPU range")
Cc: Anton Blanchard <anton@samba.org>
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo
2026-06-04 12:55:06 -03:00
parent 824b18f607
commit a5498ccf80
4 changed files with 10 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
tools/perf/builtin-annotate.c
View File

@@ -295,7 +295,8 @@ static int process_sample_event(const struct perf_tool *tool,
goto out_put;
}
if (ann->cpu_list && !test_bit(sample->cpu, ann->cpu_bitmap))
if (ann->cpu_list && (sample->cpu >= MAX_NR_CPUS ||
!test_bit(sample->cpu, ann->cpu_bitmap)))
goto out_put;
if (!al.filtered &&

3
tools/perf/builtin-diff.c
View File

@@ -416,7 +416,8 @@ static int diff__process_sample_event(const struct perf_tool *tool,
goto out;
}
if (cpu_list && !test_bit(sample->cpu, cpu_bitmap)) {
if (cpu_list && (sample->cpu >= MAX_NR_CPUS ||
!test_bit(sample->cpu, cpu_bitmap))) {
ret = 0;
goto out;
}

3
tools/perf/builtin-report.c
View File

@@ -298,7 +298,8 @@ static int process_sample_event(const struct perf_tool *tool,
if (symbol_conf.hide_unresolved && al.sym == NULL)
goto out_put;
if (rep->cpu_list && !test_bit(sample->cpu, rep->cpu_bitmap))
if (rep->cpu_list && (sample->cpu >= MAX_NR_CPUS ||
!test_bit(sample->cpu, rep->cpu_bitmap)))
goto out_put;
if (sort__mode == SORT_MODE__BRANCH) {

6
tools/perf/builtin-sched.c
View File

@@ -2192,7 +2192,8 @@ static void timehist_print_sample(struct perf_sched *sched,
char nstr[30];
u64 wait_time;
if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
if (cpu_list && (sample->cpu >= MAX_NR_CPUS ||
!test_bit(sample->cpu, cpu_bitmap)))
return;
timestamp__scnprintf_usec(t, tstr, sizeof(tstr));
@@ -2871,7 +2872,8 @@ static int timehist_sched_change_event(const struct perf_tool *tool,
}
if (!sched->idle_hist || thread__tid(thread) == 0) {
if (!cpu_list || test_bit(sample->cpu, cpu_bitmap))
if (!cpu_list || (sample->cpu < MAX_NR_CPUS &&
test_bit(sample->cpu, cpu_bitmap)))
timehist_update_runtime_stats(tr, t, tprev);
if (sched->idle_hist) {