From: Daniel Jordan daniel.m.jordan@oracle.com
[ Upstream commit 68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/pcrypt.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index a4f3b3f342c8d..276d2fd9e911c 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -79,12 +79,14 @@ 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); }
@@ -124,12 +126,14 @@ 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); }