kernel/git/stable/linux.git/crypto/skcipher.c, branch linux-4.18.y

crypto: skcipher - fix crash flushing dcache in error path

2018-08-17T19:03:49+00:00

commit 8088d3dd4d7c6933a65aa169393b5d88d8065672 upstream. scatterwalk_done() is only meant to be called after a nonzero number of bytes have been processed, since scatterwalk_pagedone() will flush the dcache of the *previous* page. But in the error case of skcipher_walk_done(), e.g. if the input wasn't an integer number of blocks, scatterwalk_done() was actually called after advancing 0 bytes. This caused a crash ("BUG: unable to handle kernel paging request") during '!PageSlab(page)' on architectures like arm and arm64 that define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was page-aligned as in that case walk->offset == 0. Fix it by reorganizing skcipher_walk_done() to skip the scatterwalk_advance() and scatterwalk_done() if an error has occurred. This bug was found by syzkaller fuzzing. Reproducer, assuming ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE: #include #include #include int main() { struct sockaddr_alg addr = { .salg_type = "skcipher", .salg_name = "cbc(aes-generic)", }; char buffer[4096] __attribute__((aligned(4096))) = { 0 }; int fd; fd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(fd, (void *)&addr, sizeof(addr)); setsockopt(fd, SOL_ALG, ALG_SET_KEY, buffer, 16); fd = accept(fd, NULL, NULL); write(fd, buffer, 15); read(fd, buffer, 15); } Reported-by: Liu Chao Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface") Cc: # v4.10+ Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: skcipher - fix aligning block size in skcipher_copy_iv()

2018-08-17T19:03:49+00:00

commit 0567fc9e90b9b1c8dbce8a5468758e6206744d4a upstream. The ALIGN() macro needs to be passed the alignment, not the alignmask (which is the alignment minus 1). Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface") Cc: # v4.10+ Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: skcipher - prevent using skciphers without setting key

2018-01-12T12:03:39+00:00

Similar to what was done for the hash API, update the skcipher API to track whether each transform has been keyed, and reject encryption/decryption if a key is needed but one hasn't been set. This isn't as important as the equivalent fix for the hash API because symmetric ciphers almost always require a key (the "null cipher" is the only exception), so are unlikely to be used without one. Still, tracking the key will prevent accidental unkeyed use. algif_skcipher also had to track the key anyway, so the new flag replaces that and simplifies the algif_skcipher implementation. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: skcipher - set walk.iv for zero-length inputs

2017-12-11T11:29:53+00:00

All the ChaCha20 algorithms as well as the ARM bit-sliced AES-XTS algorithms call skcipher_walk_virt(), then access the IV (walk.iv) before checking whether any bytes need to be processed (walk.nbytes). But if the input is empty, then skcipher_walk_virt() doesn't set the IV, and the algorithms crash trying to use the uninitialized IV pointer. Fix it by setting the IV earlier in skcipher_walk_virt(). Also fix it for the AEAD walk functions. This isn't a perfect solution because we can't actually align the IV to ->cra_alignmask unless there are bytes to process, for one because the temporary buffer for the aligned IV is freed by skcipher_walk_done(), which is only called when there are bytes to process. Thus, algorithms that require aligned IVs will still need to avoid accessing the IV when walk.nbytes == 0. Still, many algorithms/architectures are fine with IVs having any alignment, and even for those that aren't, a misaligned pointer bug is much less severe than an uninitialized pointer bug. This change also matches the behavior of the older blkcipher_walk API. Fixes: 0cabf2af6f5a ("crypto: skcipher - Fix crash on zero-length input") Reported-by: syzbot Cc: # v4.14+ Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2017-11-29T00:22:10+00:00

Pull crypto fixes from Herbert Xu: - avoid potential bogus alignment for some AEAD operations - fix crash in algif_aead - avoid sleeping in softirq context with async af_alg * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: skcipher - Fix skcipher_walk_aead_common crypto: af_alg - remove locking in async callback crypto: algif_aead - skip SGL entries with NULL page

crypto: skcipher - Fix skcipher_walk_aead_common

2017-11-25T00:08:52+00:00

The skcipher_walk_aead_common function calls scatterwalk_copychunks on the input and output walks to skip the associated data. If the AD end at an SG list entry boundary, then after these calls the walks will still be pointing to the end of the skipped region. These offsets are later checked for alignment in skcipher_walk_next, so the skcipher_walk may detect the alignment incorrectly. This patch fixes it by calling scatterwalk_done after the copychunks calls to ensure that the offsets refer to the right SG list entry. Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface") Cc: Signed-off-by: Ondrej Mosnacek Signed-off-by: Herbert Xu

crypto: skcipher - Fix crash on zero-length input

2017-10-07T04:04:32+00:00

The skcipher walk interface doesn't handle zero-length input properly as the old blkcipher walk interface did. This is due to the fact that the length check is done too late. This patch moves the length check forward so that it does the right thing. Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk...") Cc: Reported-by: Stephan Müller Signed-off-by: Herbert Xu

crypto: skcipher - Add missing API setkey checks

2017-05-18T05:04:05+00:00

The API setkey checks for key sizes and alignment went AWOL during the skcipher conversion. This patch restores them. Cc: Fixes: 4e6c3df4d729 ("crypto: skcipher - Add low-level skcipher...") Reported-by: Baozeng Signed-off-by: Herbert Xu

crypto: Replaced gcc specific attributes with macros from compiler.h

2017-01-12T16:24:39+00:00

Continuing from this commit: 52f5684c8e1e ("kernel: use macros from compiler.h instead of __attribute__((...))") I submitted 4 total patches. They are part of task I've taken up to increase compiler portability in the kernel. I've cleaned up the subsystems under /kernel /mm /block and /security, this patch targets /crypto. There is which provides macros for various gcc specific constructs. Eg: __weak for __attribute__((weak)). I've cleaned all instances of gcc specific attributes with the right macros for the crypto subsystem. I had to make one additional change into compiler-gcc.h for the case when one wants to use this: __attribute__((aligned) and not specify an alignment factor. From the gcc docs, this will result in the largest alignment for that data type on the target machine so I've named the macro __aligned_largest. Please advise if another name is more appropriate. Signed-off-by: Gideon Israel Dsouza Signed-off-by: Herbert Xu

crypto: skcipher - introduce walksize attribute for SIMD algos

2016-12-30T11:52:47+00:00

In some cases, SIMD algorithms can only perform optimally when allowed to operate on multiple input blocks in parallel. This is especially true for bit slicing algorithms, which typically take the same amount of time processing a single block or 8 blocks in parallel. However, other SIMD algorithms may benefit as well from bigger strides. So add a walksize attribute to the skcipher algorithm definition, and wire it up to the skcipher walk API. To avoid confusion between the skcipher and AEAD attributes, rename the skcipher_walk chunksize attribute to 'stride', and set it from the walksize (in the skcipher case) or from the chunksize (in the AEAD case). Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu