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authorJiri Olsa <jolsa@kernel.org>2022-09-27 22:32:59 +0200
committerPeter Zijlstra <peterz@infradead.org>2022-09-27 22:50:25 +0200
commitcce6a2d7e0e494c453ad73e1e78bd50684f20cca (patch)
tree92b2017af8a07f18b6a9b2c9aae41fb8c474b3c9 /kernel/trace
parentperf, hw_breakpoint: Fix use-after-free if perf_event_open() fails (diff)
downloadlinux-cce6a2d7e0e494c453ad73e1e78bd50684f20cca.tar.xz
linux-cce6a2d7e0e494c453ad73e1e78bd50684f20cca.zip
bpf: Check flags for branch stack in bpf_read_branch_records helper
Recent commit [1] changed branch stack data indication from br_stack pointer to sample_flags in perf_sample_data struct. We need to check sample_flags for PERF_SAMPLE_BRANCH_STACK bit for valid branch stack data. [1] a9a931e26668 ("perf: Use sample_flags for branch stack") Fixes: a9a931e26668 ("perf: Use sample_flags for branch stack") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20220927203259.590950-1-jolsa@kernel.org
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/bpf_trace.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 68e5cdd24cef..1fcd1234607e 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1507,6 +1507,9 @@ BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
return -EINVAL;
+ if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
+ return -ENOENT;
+
if (unlikely(!br_stack))
return -ENOENT;