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authorDaniel Jordan <daniel.m.jordan@oracle.com>2021-10-21 14:30:28 -0400
committerHerbert Xu <herbert@gondor.apana.org.au>2021-10-29 21:04:04 +0800
commit68b6dea802cea0dbdd8bd7ccc60716b5a32a5d8a (patch)
treecf1ee4028f64bdfd9c25ca317cedc1408fbc656c
parent83bff109616433d4cfd999e14f1ffc4759c3c1e0 (diff)
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>
-rw-r--r--crypto/pcrypt.c12
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);
}