On 26 July 2014 01:40, Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote: > cryptsetup fails on arm64 when using kernel encryption via AF_ALG socket. > See https://bugzilla.redhat.com/show_bug.cgi?id=1122937 > > The bug is caused by incorrect handling of unaligned data in > arch/arm64/crypto/aes-glue.c. Cryptsetup creates a buffer that is aligned > on 8 bytes, but not on 16 bytes. It opens AF_ALG socket and uses the > socket to encrypt data in the buffer. The arm64 crypto accelerator causes > data corruption or crashes in the scatterwalk_pagedone. > > This patch fixes the bug by passing the residue bytes that were not > processed as the last parameter to blkcipher_walk_done. > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Thanks for the patch. This correctly fixes a thinko on my part regarding the guarantees offered by the blkcipher API. Unfortunately, this wasn't caught by the tcrypt test suite, so I will propose some patches later to address cases like this. BTW using kernel crypto with AF_ALG is fairly pointless when using crypto instructions instead of crypto accelerator peripherals, should we change anything on the kernel side so we don't expose these drivers? @Catalin: this is a bug fix for the code that was merged this cycle. I would recommend to merge this for 3.16, but if not, could you please add a cc stable? Or ack it and perhaps Herbert can take both? (There is a similar patch for ARM as well) Regards, Ard. > Index: linux-3.16.0-0.rc6.git1.1.fc21.aarch64/arch/arm64/crypto/aes-glue.c > =================================================================== > --- linux-3.16.0-0.rc6.git1.1.fc21.aarch64.orig/arch/arm64/crypto/aes-glue.c > +++ linux-3.16.0-0.rc6.git1.1.fc21.aarch64/arch/arm64/crypto/aes-glue.c > @@ -106,7 +106,7 @@ static int ecb_encrypt(struct blkcipher_ > for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) { > aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key_enc, rounds, blocks, first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > return err; > @@ -128,7 +128,7 @@ static int ecb_decrypt(struct blkcipher_ > for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) { > aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key_dec, rounds, blocks, first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > return err; > @@ -151,7 +151,7 @@ static int cbc_encrypt(struct blkcipher_ > aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key_enc, rounds, blocks, walk.iv, > first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > return err; > @@ -174,7 +174,7 @@ static int cbc_decrypt(struct blkcipher_ > aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key_dec, rounds, blocks, walk.iv, > first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > return err; > @@ -243,7 +243,7 @@ static int xts_encrypt(struct blkcipher_ > aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key1.key_enc, rounds, blocks, > (u8 *)ctx->key2.key_enc, walk.iv, first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > > @@ -267,7 +267,7 @@ static int xts_decrypt(struct blkcipher_ > aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr, > (u8 *)ctx->key1.key_dec, rounds, blocks, > (u8 *)ctx->key2.key_enc, walk.iv, first); > - err = blkcipher_walk_done(desc, &walk, 0); > + err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); > } > kernel_neon_end(); > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
