From 7f9ee5fc97e14682e36fe22ae2654c07e4998b82 Mon Sep 17 00:00:00 2001 From: Shardul Bankar Date: Tue, 14 Oct 2025 17:30:37 +0530 Subject: [PATCH] bpf: test_run: Fix ctx leak in bpf_prog_test_run_xdp error path Fix a memory leak in bpf_prog_test_run_xdp() where the context buffer allocated by bpf_ctx_init() is not freed when the function returns early due to a data size check. On the failing path: ctx = bpf_ctx_init(...); if (kattr->test.data_size_in - meta_sz < ETH_HLEN) return -EINVAL; The early return bypasses the cleanup label that kfree()s ctx, leading to a leak detectable by kmemleak under fuzzing. Change the return to jump to the existing free_ctx label. Fixes: fe9544ed1a2e ("bpf: Support specifying linear xdp packet data size for BPF_PROG_TEST_RUN") Reported-by: BPF Runtime Fuzzer (BRF) Signed-off-by: Shardul Bankar Signed-off-by: Martin KaFai Lau Acked-by: Jiri Olsa Acked-by: Daniel Borkmann Link: https://patch.msgid.link/20251014120037.1981316-1-shardulsb08@gmail.com --- net/bpf/test_run.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index dfb03ee0bb62a..1782e83de2cb8 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -1269,7 +1269,7 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, goto free_ctx; if (kattr->test.data_size_in - meta_sz < ETH_HLEN) - return -EINVAL; + goto free_ctx; data = bpf_test_init(kattr, linear_sz, max_linear_sz, headroom, tailroom); if (IS_ERR(data)) { -- 2.47.3