4.20-stable review patch. If anyone has any objections, please let me know.
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From: Aymen Sghaier aymen.sghaier@nxp.com
commit 04e6d25c5bb244c1a37eb9fe0b604cc11a04e8c5 upstream.
Recent changes - probably DMA API related (generic and/or arm64-specific) - exposed a case where driver maps a zero-length buffer: ahash_init()->ahash_update()->ahash_final() with a zero-length string to hash
kernel BUG at kernel/dma/swiotlb.c:475! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 1823 Comm: cryptomgr_test Not tainted 4.20.0-rc1-00108-g00c9fe37a7f2 #1 Hardware name: LS1046A RDB Board (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc : swiotlb_tbl_map_single+0x170/0x2b8 lr : swiotlb_map_page+0x134/0x1f8 sp : ffff00000f79b8f0 x29: ffff00000f79b8f0 x28: 0000000000000000 x27: ffff0000093d0000 x26: 0000000000000000 x25: 00000000001f3ffe x24: 0000000000200000 x23: 0000000000000000 x22: 00000009f2c538c0 x21: ffff800970aeb410 x20: 0000000000000001 x19: ffff800970aeb410 x18: 0000000000000007 x17: 000000000000000e x16: 0000000000000001 x15: 0000000000000019 x14: c32cb8218a167fe8 x13: ffffffff00000000 x12: ffff80097fdae348 x11: 0000800976bca000 x10: 0000000000000010 x9 : 0000000000000000 x8 : ffff0000091fd6c8 x7 : 0000000000000000 x6 : 00000009f2c538bf x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 00000009f2c538c0 x1 : 00000000f9fff000 x0 : 0000000000000000 Process cryptomgr_test (pid: 1823, stack limit = 0x(____ptrval____)) Call trace: swiotlb_tbl_map_single+0x170/0x2b8 swiotlb_map_page+0x134/0x1f8 ahash_final_no_ctx+0xc4/0x6cc ahash_final+0x10/0x18 crypto_ahash_op+0x30/0x84 crypto_ahash_final+0x14/0x1c __test_hash+0x574/0xe0c test_hash+0x28/0x80 __alg_test_hash+0x84/0xd0 alg_test_hash+0x78/0x144 alg_test.part.30+0x12c/0x2b4 alg_test+0x3c/0x68 cryptomgr_test+0x44/0x4c kthread+0xfc/0x128 ret_from_fork+0x10/0x18 Code: d34bfc18 2a1a03f7 1a9f8694 35fff89a (d4210000)
Cc: stable@vger.kernel.org Signed-off-by: Aymen Sghaier aymen.sghaier@nxp.com Signed-off-by: Horia Geantă horia.geanta@nxp.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/caam/caamhash.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
--- a/drivers/crypto/caam/caamhash.c +++ b/drivers/crypto/caam/caamhash.c @@ -1071,13 +1071,16 @@ static int ahash_final_no_ctx(struct aha
desc = edesc->hw_desc;
- state->buf_dma = dma_map_single(jrdev, buf, buflen, DMA_TO_DEVICE); - if (dma_mapping_error(jrdev, state->buf_dma)) { - dev_err(jrdev, "unable to map src\n"); - goto unmap; - } + if (buflen) { + state->buf_dma = dma_map_single(jrdev, buf, buflen, + DMA_TO_DEVICE); + if (dma_mapping_error(jrdev, state->buf_dma)) { + dev_err(jrdev, "unable to map src\n"); + goto unmap; + }
- append_seq_in_ptr(desc, state->buf_dma, buflen, 0); + append_seq_in_ptr(desc, state->buf_dma, buflen, 0); + }
edesc->dst_dma = map_seq_out_ptr_result(desc, jrdev, req->result, digestsize);