v5: - limit AHASH_REQUEST_ON_STACK size only to non-async hash wrapping. - sanity-check ahash reqsize only when doing shash wrapping. - remove frame_warn changes in favor of shash conversions and other fixes. - send ahash to shash conversion patches and other fixes separately. v4: - add back *_REQUEST_ON_STACK patches. - programmatically find stack sizes for *_REQUEST_ON_STACK patches. - whitelist some code that trips FRAME_WARN on 32-bit builds. - fix alignment patches. v3: - drop *_REQUEST_ON_STACK patches. The rest of this series is pretty straight-forward, and I'd like to get them tested in -next while we continue to chip away at the *_REQUEST_ON_STACK VLA removal patches separately. "Part 2" will continue with those. v2: - use 512 instead of PAGE_SIZE / 8 to avoid bloat on large-page archs. - swtich xcbc to "16" max universally. - fix typo in bounds check for dm buffer size. - examine actual reqsizes for skcipher and ahash instead of guessing. - improve names and comments for alg maxes This is nearly the last of the VLA removals[1], but it's one of the largest because crypto gets used in lots of places. After looking through code, usage, reading the threads Gustavo started, and comparing the use-cases to the other VLA removals that have landed in the kernel, I think this series is likely the best way forward to shut the door on VLAs forever. As background, the crypto stack usage is for callers to do an immediate bit of work that doesn't allocate new memory. This means that other VLA removal techniques (like just using kmalloc) aren't workable, and the next common technique is needed: examination of maximum stack usage and the addition of sanity checks. This series does that, and in several cases, these maximums were already implicit in the code. This series is intended to land via the crypto tree for 4.19, though it touches dm and a few other things as well, since there are dependent patches (new crypto #defines being used, kbuild, etc). Thanks! -Kees [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx Kees Cook (11): crypto: xcbc: Remove VLA usage crypto: cbc: Remove VLA usage crypto: shash: Remove VLA usage dm integrity: Remove VLA usage crypto: ahash: Remove VLA usage dm verity fec: Remove VLA usage crypto alg: Introduce generic max blocksize and alignmask crypto: qat: Remove VLA usage crypto: shash: Remove VLA usage in unaligned hashing crypto: ahash: Remove VLA usage for AHASH_REQUEST_ON_STACK crypto: skcipher: Remove VLA usage for SKCIPHER_REQUEST_ON_STACK crypto/ahash.c | 4 +-- crypto/algapi.c | 7 +++- crypto/algif_hash.c | 2 +- crypto/shash.c | 42 +++++++++++++++--------- crypto/xcbc.c | 9 +++-- drivers/crypto/qat/qat_common/qat_algs.c | 8 +++-- drivers/md/dm-integrity.c | 23 +++++++++---- drivers/md/dm-verity-fec.c | 5 ++- include/crypto/algapi.h | 4 ++- include/crypto/cbc.h | 4 ++- include/crypto/hash.h | 19 +++++++++-- include/crypto/internal/skcipher.h | 1 + include/crypto/skcipher.h | 4 ++- include/linux/compiler-gcc.h | 1 - 14 files changed, 97 insertions(+), 36 deletions(-) -- 2.17.1
