| Message ID | 20210603055341.24473-1-liuhangbin@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | crypto: x86/curve25519 - fix cpu feature checking logic in mod_exit | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Thu, Jun 3, 2021 at 7:53 AM Hangbin Liu <liuhangbin@gmail.com> wrote: > > In curve25519_mod_init() the curve25519_alg will be registered only when > (X86_FEATURE_BMI2 && X86_FEATURE_ADX). But in curve25519_mod_exit() > it still checks (X86_FEATURE_BMI2 || X86_FEATURE_ADX) when do crypto > unregister. This will trigger a BUG_ON in crypto_unregister_alg() as > alg->cra_refcnt is 0 if the cpu only supports one of X86_FEATURE_BMI2 > and X86_FEATURE_ADX. > > Fixes: 07b586fe0662 ("crypto: x86/curve25519 - replace with formally verified implementation") > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> > --- > arch/x86/crypto/curve25519-x86_64.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c > index 6706b6cb1d0f..38caf61cd5b7 100644 > --- a/arch/x86/crypto/curve25519-x86_64.c > +++ b/arch/x86/crypto/curve25519-x86_64.c > @@ -1500,7 +1500,7 @@ static int __init curve25519_mod_init(void) > static void __exit curve25519_mod_exit(void) > { > if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && > - (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX))) > + static_branch_likely(&curve25519_use_bmi2_adx)) > crypto_unregister_kpp(&curve25519_alg); > } Looks like the error is actually that the `||` should be a `&&`. But if you'd like to branch on that static key instead, that's fine. Cc: stable@vger.kernel.org Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
On Thu, Jun 3, 2021 at 6:24 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote: > > if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && > > - (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX))) > > + static_branch_likely(&curve25519_use_bmi2_adx)) > > crypto_unregister_kpp(&curve25519_alg); > > } > > Looks like the error is actually that the `||` should be a `&&`. But > if you'd like to branch on that static key instead, that's fine. Yes, the code would be shorter by checking the static key :) Thanks hangbin
On Thu, Jun 03, 2021 at 01:53:40AM -0400, Hangbin Liu wrote: > In curve25519_mod_init() the curve25519_alg will be registered only when > (X86_FEATURE_BMI2 && X86_FEATURE_ADX). But in curve25519_mod_exit() > it still checks (X86_FEATURE_BMI2 || X86_FEATURE_ADX) when do crypto > unregister. This will trigger a BUG_ON in crypto_unregister_alg() as > alg->cra_refcnt is 0 if the cpu only supports one of X86_FEATURE_BMI2 > and X86_FEATURE_ADX. > > Fixes: 07b586fe0662 ("crypto: x86/curve25519 - replace with formally verified implementation") > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> > --- > arch/x86/crypto/curve25519-x86_64.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Patch applied. Thanks.
diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c index 6706b6cb1d0f..38caf61cd5b7 100644 --- a/arch/x86/crypto/curve25519-x86_64.c +++ b/arch/x86/crypto/curve25519-x86_64.c @@ -1500,7 +1500,7 @@ static int __init curve25519_mod_init(void) static void __exit curve25519_mod_exit(void) { if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && - (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX))) + static_branch_likely(&curve25519_use_bmi2_adx)) crypto_unregister_kpp(&curve25519_alg); }
In curve25519_mod_init() the curve25519_alg will be registered only when (X86_FEATURE_BMI2 && X86_FEATURE_ADX). But in curve25519_mod_exit() it still checks (X86_FEATURE_BMI2 || X86_FEATURE_ADX) when do crypto unregister. This will trigger a BUG_ON in crypto_unregister_alg() as alg->cra_refcnt is 0 if the cpu only supports one of X86_FEATURE_BMI2 and X86_FEATURE_ADX. Fixes: 07b586fe0662 ("crypto: x86/curve25519 - replace with formally verified implementation") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> --- arch/x86/crypto/curve25519-x86_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)