On 26 July 2014 15:13, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > 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) > ... only this patch fails to repair the ECB case. @Mikulas: could you do a v2 and include ECB encryption/decryption? Cheers, 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
