| Message ID | 20190403152602.10019-1-steven.price@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | PM / devfreq: return PTR_ERR not NULL in try_then_request_governor() | expand |
Hi, Missatge de Steven Price <steven.price@arm.com> del dia dc., 3 d’abr. 2019 a les 17:26: > > The callers of try_then_request_governor() only test for a PTR_ERR using > IS_ERR(). However in the case that request_module() fails then NULL is > currently returned which will cause a NULL-pointer dereference in the > caller. > > Instead convert the error we already have to a valid PTR_ERR and return > it. > > Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.") > Signed-off-by: Steven Price <steven.price@arm.com> There is already a fix for that. The fix was initially sent in October [2] but unfortunately, it got lost. I resend and now is queued [1]. Hopefully, the Fixes tag will help to pick the fix to the proper kernel releases. Thanks, Enric [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b53b0128052ffd687797d5f4deeb76327e7b5711 [2] https://lkml.org/lkml/2018/10/16/744 > --- > drivers/devfreq/devfreq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0ae3de76833b..d29f66f0e52a 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name) > /* Restore previous state before return */ > mutex_lock(&devfreq_list_lock); > if (err) > - return NULL; > + return ERR_PTR(err); > > governor = find_devfreq_governor(name); > } > -- > 2.20.1 >
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 0ae3de76833b..d29f66f0e52a 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name) /* Restore previous state before return */ mutex_lock(&devfreq_list_lock); if (err) - return NULL; + return ERR_PTR(err); governor = find_devfreq_governor(name); }
The callers of try_then_request_governor() only test for a PTR_ERR using IS_ERR(). However in the case that request_module() fails then NULL is currently returned which will cause a NULL-pointer dereference in the caller. Instead convert the error we already have to a valid PTR_ERR and return it. Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.") Signed-off-by: Steven Price <steven.price@arm.com> --- drivers/devfreq/devfreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)