[PATCH 4.19 094/205] crypto: hisilicon - Fix NULL dereference for same dst and src

Greg Kroah-Hartman
2018-11-19T16:34:19Z

From: John Garry <john.garry@huawei.com>

commit 68a031d22c57b94870ba13513c9d93b8a8119ab2 upstream.

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/crypto/hisilicon/sec/sec_algs.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/crypto/hisilicon/sec/sec_algs.c
+++ b/drivers/crypto/hisilicon/sec/sec_algs.c
@@ -732,6 +732,7 @@ static int sec_alg_skcipher_crypto(struc
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(struc
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(struc
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 @@ err_free_elements:
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);