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| author |   Daniel Jordan <daniel.m.jordan@oracle.com> | 2021-10-21 14:30:28 -0400 |
|---|---|---|
| committer |   Herbert Xu <herbert@gondor.apana.org.au> | 2021-10-29 21:04:04 +0800 |
| commit | 68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a (patch) | |
| tree | cf1ee4028f64bdfd9c25ca317cedc1408fbc656c /crypto | |
| parent | crypto: ccp - Make use of the helper macro kthread_run() (diff) | |
| download | linux-dev-68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a.tar.xz linux-dev-68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a.zip | |
crypto: pcrypt - Delay write to padata->info
These three events can race when pcrypt is used multiple times in a
template ("pcrypt(pcrypt(...))"):
1. [taskA] The caller makes the crypto request via crypto_aead_encrypt()
2. [kworkerB] padata serializes the inner pcrypt request
3. [kworkerC] padata serializes the outer pcrypt request
3 might finish before the call to crypto_aead_encrypt() returns in 1,
resulting in two possible issues.
First, a use-after-free of the crypto request's memory when, for
example, taskA writes to the outer pcrypt request's padata->info in
pcrypt_aead_enc() after kworkerC completes the request.
Second, the outer pcrypt request overwrites the inner pcrypt request's
return code with -EINPROGRESS, making a successful request appear to
fail. For instance, kworkerB writes the outer pcrypt request's
padata->info in pcrypt_aead_done() and then taskA overwrites it
in pcrypt_aead_enc().
Avoid both situations by delaying the write of padata->info until after
the inner crypto request's return code is checked. This prevents the
use-after-free by not touching the crypto request's memory after the
next-inner crypto request is made, and stops padata->info from being
overwritten.
Fixes: 5068c7a883d16 ("crypto: pcrypt - Add pcrypt crypto parallelization wrapper")
Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/pcrypt.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index d569c7ed6c80..9d10b846ccf7 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -78,12 +78,14 @@ static void pcrypt_aead_enc(struct padata_priv *padata) { struct pcrypt_request *preq = pcrypt_padata_request(padata); struct aead_request *req = pcrypt_request_ctx(preq); + int ret; - padata->info = crypto_aead_encrypt(req); + ret = crypto_aead_encrypt(req); - if (padata->info == -EINPROGRESS) + if (ret == -EINPROGRESS) return; + padata->info = ret; padata_do_serial(padata); } @@ -123,12 +125,14 @@ static void pcrypt_aead_dec(struct padata_priv *padata) { struct pcrypt_request *preq = pcrypt_padata_request(padata); struct aead_request *req = pcrypt_request_ctx(preq); + int ret; - padata->info = crypto_aead_decrypt(req); + ret = crypto_aead_decrypt(req); - if (padata->info == -EINPROGRESS) + if (ret == -EINPROGRESS) return; + padata->info = ret; padata_do_serial(padata); } |