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authorHerbert Xu <herbert@gondor.apana.org.au>2019-11-26 15:58:45 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2019-12-11 16:36:45 +0800
commitbbefa1dd6a6d53537c11624752219e39959d04fb (patch)
treee96ab2235faf325a1112f9f2a51b8fa70704ca46 /crypto
parent45a536e3a7e0aeba257c708e023482df3b4ec052 (diff)
crypto: pcrypt - Avoid deadlock by using per-instance padata queues
If the pcrypt template is used multiple times in an algorithm, then a deadlock occurs because all pcrypt instances share the same padata_instance, which completes requests in the order submitted. That is, the inner pcrypt request waits for the outer pcrypt request while the outer request is already waiting for the inner. This patch fixes this by allocating a set of queues for each pcrypt instance instead of using two global queues. In order to maintain the existing user-space interface, the pinst structure remains global so any sysfs modifications will apply to every pcrypt instance. Note that when an update occurs we have to allocate memory for every pcrypt instance. Should one of the allocations fail we will abort the update without rolling back changes already made. The new per-instance data structure is called padata_shell and is essentially a wrapper around parallel_data. Reproducer: #include <linux/if_alg.h> #include <sys/socket.h> #include <unistd.h> int main() { struct sockaddr_alg addr = { .salg_type = "aead", .salg_name = "pcrypt(pcrypt(rfc4106-gcm-aesni))" }; int algfd, reqfd; char buf[32] = { 0 }; algfd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(algfd, (void *)&addr, sizeof(addr)); setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, 20); reqfd = accept(algfd, 0, 0); write(reqfd, buf, 32); read(reqfd, buf, 16); } Reported-by: syzbot+56c7151cad94eec37c521f0e47d2eee53f9361c4@syzkaller.appspotmail.com Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto parallelization wrapper") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/pcrypt.c36
1 files changed, 33 insertions, 3 deletions
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 81bbea7f2ba6..3e026e7a7e75 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -24,6 +24,8 @@ static struct kset *pcrypt_kset;
struct pcrypt_instance_ctx {
struct crypto_aead_spawn spawn;
+ struct padata_shell *psenc;
+ struct padata_shell *psdec;
atomic_t tfm_count;
};
@@ -32,6 +34,12 @@ struct pcrypt_aead_ctx {
unsigned int cb_cpu;
};
+static inline struct pcrypt_instance_ctx *pcrypt_tfm_ictx(
+ struct crypto_aead *tfm)
+{
+ return aead_instance_ctx(aead_alg_instance(tfm));
+}
+
static int pcrypt_aead_setkey(struct crypto_aead *parent,
const u8 *key, unsigned int keylen)
{
@@ -90,6 +98,9 @@ static int pcrypt_aead_encrypt(struct aead_request *req)
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
u32 flags = aead_request_flags(req);
+ struct pcrypt_instance_ctx *ictx;
+
+ ictx = pcrypt_tfm_ictx(aead);
memset(padata, 0, sizeof(struct padata_priv));
@@ -103,7 +114,7 @@ static int pcrypt_aead_encrypt(struct aead_request *req)
req->cryptlen, req->iv);
aead_request_set_ad(creq, req->assoclen);
- err = padata_do_parallel(pencrypt, padata, &ctx->cb_cpu);
+ err = padata_do_parallel(ictx->psenc, padata, &ctx->cb_cpu);
if (!err)
return -EINPROGRESS;
@@ -132,6 +143,9 @@ static int pcrypt_aead_decrypt(struct aead_request *req)
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
u32 flags = aead_request_flags(req);
+ struct pcrypt_instance_ctx *ictx;
+
+ ictx = pcrypt_tfm_ictx(aead);
memset(padata, 0, sizeof(struct padata_priv));
@@ -145,7 +159,7 @@ static int pcrypt_aead_decrypt(struct aead_request *req)
req->cryptlen, req->iv);
aead_request_set_ad(creq, req->assoclen);
- err = padata_do_parallel(pdecrypt, padata, &ctx->cb_cpu);
+ err = padata_do_parallel(ictx->psdec, padata, &ctx->cb_cpu);
if (!err)
return -EINPROGRESS;
@@ -192,6 +206,8 @@ static void pcrypt_free(struct aead_instance *inst)
struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst);
crypto_drop_aead(&ctx->spawn);
+ padata_free_shell(ctx->psdec);
+ padata_free_shell(ctx->psenc);
kfree(inst);
}
@@ -233,12 +249,22 @@ static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
if (!inst)
return -ENOMEM;
+ err = -ENOMEM;
+
ctx = aead_instance_ctx(inst);
+ ctx->psenc = padata_alloc_shell(pencrypt);
+ if (!ctx->psenc)
+ goto out_free_inst;
+
+ ctx->psdec = padata_alloc_shell(pdecrypt);
+ if (!ctx->psdec)
+ goto out_free_psenc;
+
crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
if (err)
- goto out_free_inst;
+ goto out_free_psdec;
alg = crypto_spawn_aead_alg(&ctx->spawn);
err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
@@ -271,6 +297,10 @@ out:
out_drop_aead:
crypto_drop_aead(&ctx->spawn);
+out_free_psdec:
+ padata_free_shell(ctx->psdec);
+out_free_psenc:
+ padata_free_shell(ctx->psenc);
out_free_inst:
kfree(inst);
goto out;