crypto: x86/chacha - avoid sleeping under kernel_fpu_begin()

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Passing atomic=true to skcipher_walk_virt() only makes the later
skcipher_walk_done() calls use atomic memory allocations, not
skcipher_walk_virt() itself.  Thus, we have to move it outside of the
preemption-disabled region (kernel_fpu_begin()/kernel_fpu_end()).

(skcipher_walk_virt() only allocates memory for certain layouts of the
input scatterlist, hence why I didn't notice this earlier...)

Reported-by: syzbot+9bf843c33f782d73ae7d@syzkaller.appspotmail.com
Fixes: 4af7826187 ("crypto: x86/chacha20 - add XChaCha20 support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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Eric Biggers 2018-12-15 12:40:17 -08:00 • committed by Herbert Xu

parent c9613335bf

commit f9c9bdb513

1 changed files with 20 additions and 13 deletions

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arch/x86/crypto/chacha_glue.c

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