Commit 3aa9b9a1 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
Browse files

selftests/bpf: Extend crypto_sanity selftest with invalid dst buffer 



Small cleanup and test extension to probe the bpf_crypto_{encrypt,decrypt}()
kfunc when a bad dst buffer is passed in to assert that an error is returned.

Also, encrypt_sanity() and skb_crypto_setup() were explicit to set the global
status variable to zero before any test, so do the same for decrypt_sanity().
Do not explicitly zero the on-stack err before bpf_crypto_ctx_create() given
the kfunc is expected to do it internally for the success case.

Before kernel fix:

  # ./vmtest.sh -- ./test_progs -t crypto
  [...]
  [    1.531200] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.533388] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  #87/1    crypto_basic/crypto_release:OK
  #87/2    crypto_basic/crypto_acquire:OK
  #87      crypto_basic:OK
  test_crypto_sanity:PASS:skel open 0 nsec
  test_crypto_sanity:PASS:ip netns add crypto_sanity_ns 0 nsec
  test_crypto_sanity:PASS:ip -net crypto_sanity_ns -6 addr add face::1/128 dev lo nodad 0 nsec
  test_crypto_sanity:PASS:ip -net crypto_sanity_ns link set dev lo up 0 nsec
  test_crypto_sanity:PASS:open_netns 0 nsec
  test_crypto_sanity:PASS:AF_ALG init fail 0 nsec
  test_crypto_sanity:PASS:if_nametoindex lo 0 nsec
  test_crypto_sanity:PASS:skb_crypto_setup fd 0 nsec
  test_crypto_sanity:PASS:skb_crypto_setup 0 nsec
  test_crypto_sanity:PASS:skb_crypto_setup retval 0 nsec
  test_crypto_sanity:PASS:skb_crypto_setup status 0 nsec
  test_crypto_sanity:PASS:create qdisc hook 0 nsec
  test_crypto_sanity:PASS:make_sockaddr 0 nsec
  test_crypto_sanity:PASS:attach encrypt filter 0 nsec
  test_crypto_sanity:PASS:encrypt socket 0 nsec
  test_crypto_sanity:PASS:encrypt send 0 nsec
  test_crypto_sanity:FAIL:encrypt status unexpected error: -5 (errno 95)
  #88      crypto_sanity:FAIL
  Summary: 1/2 PASSED, 0 SKIPPED, 1 FAILED

After kernel fix:

  # ./vmtest.sh -- ./test_progs -t crypto
  [...]
  [    1.540963] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.542404] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  #87/1    crypto_basic/crypto_release:OK
  #87/2    crypto_basic/crypto_acquire:OK
  #87      crypto_basic:OK
  #88      crypto_sanity:OK
  Summary: 2/2 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/r/20250829143657.318524-2-daniel@iogearbox.net


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f9bb6ffa

tools/testing/selftests/bpf/progs/crypto_sanity.c

+32 −14
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ unsigned char key[256] = {}; 
u16 udp_test_port = 7777;

u32 authsize, key_len;

char algo[128] = {};

char dst[16] = {};

char dst[16] = {}, dst_bad[8] = {};

int status;



static int skb_dynptr_validate(struct __sk_buff *skb, struct bpf_dynptr *psrc)
@@ -59,10 +59,9 @@ int skb_crypto_setup(void *ctx) 
		.authsize = authsize,

	};

	struct bpf_crypto_ctx *cctx;

	int err = 0;

	int err;



	status = 0;



	if (key_len > 256) {

		status = -EINVAL;

		return 0;
@@ -70,8 +69,8 @@ int skb_crypto_setup(void *ctx) 


	__builtin_memcpy(&params.algo, algo, sizeof(algo));

	__builtin_memcpy(&params.key, key, sizeof(key));

	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);



	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);

	if (!cctx) {

		status = err;

		return 0;
@@ -80,7 +79,6 @@ int skb_crypto_setup(void *ctx) 
	err = crypto_ctx_insert(cctx);

	if (err && err != -EEXIST)

		status = err;



	return 0;

}
@@ -92,6 +90,7 @@ int decrypt_sanity(struct __sk_buff *skb) 
	struct bpf_dynptr psrc, pdst;

	int err;



	status = 0;

	err = skb_dynptr_validate(skb, &psrc);

	if (err < 0) {

		status = err;
@@ -110,13 +109,23 @@ int decrypt_sanity(struct __sk_buff *skb) 
		return TC_ACT_SHOT;

	}



	/* dst is a global variable to make testing part easier to check. In real

	 * production code, a percpu map should be used to store the result.

	/* Check also bad case where the dst buffer is smaller than the

	 * skb's linear section.

	 */

	bpf_dynptr_from_mem(dst_bad, sizeof(dst_bad), 0, &pdst);

	status = bpf_crypto_decrypt(ctx, &psrc, &pdst, NULL);

	if (!status)

		status = -EIO;

	if (status != -EINVAL)

		goto err;



	/* dst is a global variable to make testing part easier to check.

	 * In real production code, a percpu map should be used to store

	 * the result.

	 */

	bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);



	status = bpf_crypto_decrypt(ctx, &psrc, &pdst, NULL);



err:

	return TC_ACT_SHOT;

}
@@ -129,7 +138,6 @@ int encrypt_sanity(struct __sk_buff *skb) 
	int err;



	status = 0;



	err = skb_dynptr_validate(skb, &psrc);

	if (err < 0) {

		status = err;
@@ -148,13 +156,23 @@ int encrypt_sanity(struct __sk_buff *skb) 
		return TC_ACT_SHOT;

	}



	/* dst is a global variable to make testing part easier to check. In real

	 * production code, a percpu map should be used to store the result.

	/* Check also bad case where the dst buffer is smaller than the

	 * skb's linear section.

	 */

	bpf_dynptr_from_mem(dst_bad, sizeof(dst_bad), 0, &pdst);

	status = bpf_crypto_encrypt(ctx, &psrc, &pdst, NULL);

	if (!status)

		status = -EIO;

	if (status != -EINVAL)

		goto err;



	/* dst is a global variable to make testing part easier to check.

	 * In real production code, a percpu map should be used to store

	 * the result.

	 */

	bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);



	status = bpf_crypto_encrypt(ctx, &psrc, &pdst, NULL);



err:

	return TC_ACT_SHOT;

}