Re: [PATCH bpf v1] selftests/bpf: Fix a memory leak in xdp_flowtable test

[Subbaraya Sundeep <sbhatta@marvell.com>]

On 2026-02-25 at 06:03:51, Ihor Solodrai (ihor.solodrai@linux.dev) wrote:
> test_progs run with ASAN reported [1]:
> 
>   ==126==ERROR: LeakSanitizer: detected memory leaks
> 
>   Direct leak of 32 byte(s) in 1 object(s) allocated from:
>       #0 0x7f1ff3cfa340 in calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:77
>       #1 0x5610c15bb520 in bpf_program_attach_fd /codebuild/output/src685977285/src/actions-runner/_work/vmtest/vmtest/src/tools/lib/bpf/libbpf.c:13164
>       #2 0x5610c15bb740 in bpf_program__attach_xdp /codebuild/output/src685977285/src/actions-runner/_work/vmtest/vmtest/src/tools/lib/bpf/libbpf.c:13204
>       #3 0x5610c14f91d3 in test_xdp_flowtable /codebuild/output/src685977285/src/actions-runner/_work/vmtest/vmtest/src/tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c:138
>       #4 0x5610c1533566 in run_one_test /codebuild/output/src685977285/src/actions-runner/_work/vmtest/vmtest/src/tools/testing/selftests/bpf/test_progs.c:1406
>       #5 0x5610c1537fb0 in main /codebuild/output/src685977285/src/actions-runner/_work/vmtest/vmtest/src/tools/testing/selftests/bpf/test_progs.c:2097
>       #6 0x7f1ff25df1c9  (/lib/x86_64-linux-gnu/libc.so.6+0x2a1c9) (BuildId: 8e9fd827446c24067541ac5390e6f527fb5947bb)
>       #7 0x7f1ff25df28a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28a) (BuildId: 8e9fd827446c24067541ac5390e6f527fb5947bb)
>       #8 0x5610c0bd3180 in _start (/tmp/work/vmtest/vmtest/selftests/bpf/test_progs+0x593180) (BuildId: cdf9f103f42307dc0a2cd6cfc8afcbc1366cf8bd)
> 
> Fix by properly destroying bpf_link on exit in xdp_flowtable test.
> 
> [1] https://github.com/kernel-patches/vmtest/actions/runs/22361085418/job/64716490680
> 
> Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>

Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>

Thanks,
Sundeep
> 
> ---
> 
> This should've been part of the recent series. I missed this locally
> because the test is skipped if nftables is not installed.
> 
> ---
>  tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c b/tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c
> index 3f9146d83d79..325e0b64dc35 100644
> --- a/tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c
> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_flowtable.c
> @@ -67,7 +67,7 @@ void test_xdp_flowtable(void)
>  	struct nstoken *tok = NULL;
>  	int iifindex, stats_fd;
>  	__u32 value, key = 0;
> -	struct bpf_link *link;
> +	struct bpf_link *link = NULL;
>  
>  	if (SYS_NOFAIL("nft -v")) {
>  		fprintf(stdout, "Missing required nft tool\n");
> @@ -160,6 +160,7 @@ void test_xdp_flowtable(void)
>  
>  	ASSERT_GE(value, N_PACKETS - 2, "bpf_xdp_flow_lookup failed");
>  out:
> +	bpf_link__destroy(link);
>  	xdp_flowtable__destroy(skel);
>  	if (tok)
>  		close_netns(tok);
> -- 
> 2.53.0
>