| Message ID | ff7a28cddfc28e7a3fb8292c680510f35ec54391.1728898147.git.lukas@wunner.de |
|---|---|
| State | Accepted |
| Commit | b358f23ab11ad8534ed0f2096cbb2411ea62f8d3 |
| Headers | show |
| Series | [cryptodev-2.6] crypto: sig - Fix oops on KEYCTL_PKEY_QUERY for RSA keys | expand |
On Mon, Oct 14, 2024 at 11:43:01AM +0200, Lukas Wunner wrote: > Commit a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size > calculation into template") introduced ->max_size() and ->digest_size() > callbacks to struct sig_alg. They return an algorithm's maximum > signature size and digest size, respectively. > > For algorithms which lack these callbacks, crypto_register_sig() was > amended to use the ->key_size() callback instead. > > However the commit neglected to also amend sig_register_instance(). > As a result, the ->max_size() and ->digest_size() callbacks remain NULL > pointers if instances do not define them. A KEYCTL_PKEY_QUERY system > call results in an oops for such instances: > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > Call Trace: > software_key_query+0x169/0x370 > query_asymmetric_key+0x67/0x90 > keyctl_pkey_query+0x86/0x120 > __do_sys_keyctl+0x428/0x480 > do_syscall_64+0x4b/0x110 > > The only instances affected by this are "pkcs1(rsa, ...)". > > Fix by moving the callback checks from crypto_register_sig() to > sig_prepare_alg(), which is also invoked by sig_register_instance(). > Change the return type of sig_prepare_alg() from void to int to be able > to return errors. This matches other algorithm types, see e.g. > aead_prepare_alg() or ahash_prepare_alg(). > > Fixes: a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size calculation into template") > Signed-off-by: Lukas Wunner <lukas@wunner.de> > --- > crypto/sig.c | 36 ++++++++++++++++++++++++------------ > 1 file changed, 24 insertions(+), 12 deletions(-) Patch applied. Thanks.
diff --git a/crypto/sig.c b/crypto/sig.c index be5ac0e59384..5e1f1f739da2 100644 --- a/crypto/sig.c +++ b/crypto/sig.c @@ -84,15 +84,6 @@ struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask) } EXPORT_SYMBOL_GPL(crypto_alloc_sig); -static void sig_prepare_alg(struct sig_alg *alg) -{ - struct crypto_alg *base = &alg->base; - - base->cra_type = &crypto_sig_type; - base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; - base->cra_flags |= CRYPTO_ALG_TYPE_SIG; -} - static int sig_default_sign(struct crypto_sig *tfm, const void *src, unsigned int slen, void *dst, unsigned int dlen) @@ -113,7 +104,7 @@ static int sig_default_set_key(struct crypto_sig *tfm, return -ENOSYS; } -int crypto_register_sig(struct sig_alg *alg) +static int sig_prepare_alg(struct sig_alg *alg) { struct crypto_alg *base = &alg->base; @@ -132,7 +123,22 @@ int crypto_register_sig(struct sig_alg *alg) if (!alg->digest_size) alg->digest_size = alg->key_size; - sig_prepare_alg(alg); + base->cra_type = &crypto_sig_type; + base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; + base->cra_flags |= CRYPTO_ALG_TYPE_SIG; + + return 0; +} + +int crypto_register_sig(struct sig_alg *alg) +{ + struct crypto_alg *base = &alg->base; + int err; + + err = sig_prepare_alg(alg); + if (err) + return err; + return crypto_register_alg(base); } EXPORT_SYMBOL_GPL(crypto_register_sig); @@ -146,9 +152,15 @@ EXPORT_SYMBOL_GPL(crypto_unregister_sig); int sig_register_instance(struct crypto_template *tmpl, struct sig_instance *inst) { + int err; + if (WARN_ON(!inst->free)) return -EINVAL; - sig_prepare_alg(&inst->alg); + + err = sig_prepare_alg(&inst->alg); + if (err) + return err; + return crypto_register_instance(tmpl, sig_crypto_instance(inst)); } EXPORT_SYMBOL_GPL(sig_register_instance);
Commit a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size calculation into template") introduced ->max_size() and ->digest_size() callbacks to struct sig_alg. They return an algorithm's maximum signature size and digest size, respectively. For algorithms which lack these callbacks, crypto_register_sig() was amended to use the ->key_size() callback instead. However the commit neglected to also amend sig_register_instance(). As a result, the ->max_size() and ->digest_size() callbacks remain NULL pointers if instances do not define them. A KEYCTL_PKEY_QUERY system call results in an oops for such instances: BUG: kernel NULL pointer dereference, address: 0000000000000000 Call Trace: software_key_query+0x169/0x370 query_asymmetric_key+0x67/0x90 keyctl_pkey_query+0x86/0x120 __do_sys_keyctl+0x428/0x480 do_syscall_64+0x4b/0x110 The only instances affected by this are "pkcs1(rsa, ...)". Fix by moving the callback checks from crypto_register_sig() to sig_prepare_alg(), which is also invoked by sig_register_instance(). Change the return type of sig_prepare_alg() from void to int to be able to return errors. This matches other algorithm types, see e.g. aead_prepare_alg() or ahash_prepare_alg(). Fixes: a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size calculation into template") Signed-off-by: Lukas Wunner <lukas@wunner.de> --- crypto/sig.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-)