@@ -732,6 +732,7 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
int *splits_in_nents;
int *splits_out_nents = NULL;
struct sec_request_el *el, *temp;
+ bool split = skreq->src != skreq->dst;
mutex_init(&sec_req->lock);
sec_req->req_base = &skreq->base;
@@ -750,7 +751,7 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
if (ret)
goto err_free_split_sizes;
- if (skreq->src != skreq->dst) {
+ if (split) {
sec_req->len_out = sg_nents(skreq->dst);
ret = sec_map_and_split_sg(skreq->dst, split_sizes, steps,
&splits_out, &splits_out_nents,
@@ -785,8 +786,9 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
split_sizes[i],
skreq->src != skreq->dst,
splits_in[i], splits_in_nents[i],
- splits_out[i],
- splits_out_nents[i], info);
+ split ? splits_out[i] : NULL,
+ split ? splits_out_nents[i] : 0,
+ info);
if (IS_ERR(el)) {
ret = PTR_ERR(el);
goto err_free_elements;
@@ -854,7 +856,7 @@ static int sec_alg_skcipher_crypto(struct skcipher_request *skreq,
crypto_skcipher_ivsize(atfm),
DMA_BIDIRECTIONAL);
err_unmap_out_sg:
- if (skreq->src != skreq->dst)
+ if (split)
sec_unmap_sg_on_err(skreq->dst, steps, splits_out,
splits_out_nents, sec_req->len_out,
info->dev);
When the source and destination addresses for the cipher are the same, we will get a NULL dereference from accessing the split destination scatterlist memories, as shown: [ 56.565719] tcrypt: [ 56.565719] testing speed of async ecb(aes) (hisi_sec_aes_ecb) encryption [ 56.574683] tcrypt: test 0 (128 bit key, 16 byte blocks): [ 56.587585] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 56.596361] Mem abort info: [ 56.599151] ESR = 0x96000006 [ 56.602196] Exception class = DABT (current EL), IL = 32 bits [ 56.608105] SET = 0, FnV = 0 [ 56.611149] EA = 0, S1PTW = 0 [ 56.614280] Data abort info: [ 56.617151] ISV = 0, ISS = 0x00000006 [ 56.620976] CM = 0, WnR = 0 [ 56.623930] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) [ 56.630533] [0000000000000000] pgd=0000041fc7e4d003, pud=0000041fcd9bf003, pmd=0000000000000000 [ 56.639224] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 56.644782] Modules linked in: tcrypt(+) [ 56.648695] CPU: 21 PID: 2326 Comm: insmod Tainted: G W 4.19.0-rc6-00001-g3fabfb8-dirty #716 [ 56.658420] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT17 Nemo 2.0 RC0 10/05/2018 [ 56.667537] pstate: 20000005 (nzCv daif -PAN -UAO) [ 56.672322] pc : sec_alg_skcipher_crypto+0x318/0x748 [ 56.677274] lr : sec_alg_skcipher_crypto+0x178/0x748 [ 56.682224] sp : ffff0000118e3840 [ 56.685525] x29: ffff0000118e3840 x28: ffff841fbb3f8118 [ 56.690825] x27: 0000000000000000 x26: 0000000000000000 [ 56.696125] x25: ffff841fbb3f8080 x24: ffff841fbadc0018 [ 56.701425] x23: ffff000009119000 x22: ffff841fbb24e280 [ 56.706724] x21: ffff841ff212e780 x20: ffff841ff212e700 [ 56.712023] x19: 0000000000000001 x18: ffffffffffffffff [ 56.717322] x17: 0000000000000000 x16: 0000000000000000 [ 56.722621] x15: ffff0000091196c8 x14: 72635f7265687069 [ 56.727920] x13: 636b735f676c615f x12: ffff000009119940 [ 56.733219] x11: 0000000000000000 x10: 00000000006080c0 [ 56.738519] x9 : 0000000000000000 x8 : ffff841fbb24e480 [ 56.743818] x7 : ffff841fbb24e500 x6 : ffff841ff00cdcc0 [ 56.749117] x5 : 0000000000000010 x4 : 0000000000000000 [ 56.754416] x3 : ffff841fbb24e380 x2 : ffff841fbb24e480 [ 56.759715] x1 : 0000000000000000 x0 : ffff000008f682c8 [ 56.765016] Process insmod (pid: 2326, stack limit = 0x(____ptrval____)) [ 56.771702] Call trace: [ 56.774136] sec_alg_skcipher_crypto+0x318/0x748 [ 56.778740] sec_alg_skcipher_encrypt+0x10/0x18 [ 56.783259] test_skcipher_speed+0x2a0/0x700 [tcrypt] [ 56.788298] do_test+0x18f8/0x48c8 [tcrypt] [ 56.792469] tcrypt_mod_init+0x60/0x1000 [tcrypt] [ 56.797161] do_one_initcall+0x5c/0x178 [ 56.800985] do_init_module+0x58/0x1b4 [ 56.804721] load_module+0x1da4/0x2150 [ 56.808456] __se_sys_init_module+0x14c/0x1e8 [ 56.812799] __arm64_sys_init_module+0x18/0x20 [ 56.817231] el0_svc_common+0x60/0xe8 [ 56.820880] el0_svc_handler+0x2c/0x80 [ 56.824615] el0_svc+0x8/0xc [ 56.827483] Code: a94c87a3 910b2000 f87b7842 f9004ba2 (b87b7821) [ 56.833564] ---[ end trace 0f63290590e93d94 ]--- Segmentation fault Fix this by only accessing these memories when we have different src and dst. Fixes: 915e4e8413da ("crypto: hisilicon - SEC security accelerator driver") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: John Garry <john.garry@huawei.com> --- drivers/crypto/hisilicon/sec/sec_algs.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)