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author | Eric Biggers <ebiggers@google.com> | 2019-01-07 15:15:59 -0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-13 10:05:32 +0100 |
commit | 557f16c7fe26a2d16013c2821c5ce5a90a7da97e (patch) | |
tree | 49a1f16236426c2bb49f0e7e814018777ede8eb3 | |
parent | 69c1fd103bbb9afe3a6b345a3e026a627257d76b (diff) | |
download | linux-stable-557f16c7fe26a2d16013c2821c5ce5a90a7da97e.tar.gz linux-stable-557f16c7fe26a2d16013c2821c5ce5a90a7da97e.tar.bz2 linux-stable-557f16c7fe26a2d16013c2821c5ce5a90a7da97e.zip |
crypto: x86/chacha20 - avoid sleeping with preemption disabled
In chacha20-simd, clear the MAY_SLEEP flag in the blkcipher_desc to
prevent sleeping with preemption disabled, under kernel_fpu_begin().
This was fixed upstream incidentally by a large refactoring,
commit 9ae433bc79f9 ("crypto: chacha20 - convert generic and x86
versions to skcipher"). But syzkaller easily trips over this when
running on older kernels, as it's easily reachable via AF_ALG.
Therefore, this patch makes the minimal fix for older kernels.
Fixes: c9320b6dcb89 ("crypto: chacha20 - Add a SSSE3 SIMD variant for x86_64")
Cc: linux-crypto@vger.kernel.org
Cc: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | arch/x86/crypto/chacha20_glue.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/crypto/chacha20_glue.c b/arch/x86/crypto/chacha20_glue.c index 8baaff5af0b5..75b9d43069f1 100644 --- a/arch/x86/crypto/chacha20_glue.c +++ b/arch/x86/crypto/chacha20_glue.c @@ -77,6 +77,7 @@ static int chacha20_simd(struct blkcipher_desc *desc, struct scatterlist *dst, blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE); + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; crypto_chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv); |