diff mbox series

fprobe: Fix to allocate entry_data_size buffer with rethook instances

Message ID 170920576727.107552.638161246679734051.stgit@devnote2
State New
Headers
Series fprobe: Fix to allocate entry_data_size buffer with rethook instances |

Commit Message

Masami Hiramatsu (Google) Feb. 29, 2024, 11:22 a.m. UTC 
  From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Fix to allocate fprobe::entry_data_size buffer with rethook instances.
If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
fprobe entry handler can cause a buffer overrun when storing entry data in
entry handler.

Reported-by: Jiri Olsa <olsajiri@gmail.com>
Fixes: 4bbd93455659 ("kprobes: kretprobe scalability improvement")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/fprobe.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Comments

Masami Hiramatsu (Google) Feb. 29, 2024, 11:28 a.m. UTC | #1 
On Thu, 29 Feb 2024 20:22:47 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Fix to allocate fprobe::entry_data_size buffer with rethook instances.
> If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
> fprobe entry handler can cause a buffer overrun when storing entry data in
> entry handler.
> 

Oops, missed a URL.

> Reported-by: Jiri Olsa <olsajiri@gmail.com>

Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/

Thanks,

> Fixes: 4bbd93455659 ("kprobes: kretprobe scalability improvement")
> Cc: stable@vger.kernel.org
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  kernel/trace/fprobe.c |   14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index 6cd2a4e3afb8..9ff018245840 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
>  {
>  	int size;
>  
> -	if (num <= 0)
> -		return -EINVAL;
> -
>  	if (!fp->exit_handler) {
>  		fp->rethook = NULL;
>  		return 0;
> @@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
>  
>  	/* Initialize rethook if needed */
>  	if (fp->nr_maxactive)
> -		size = fp->nr_maxactive;
> +		num = fp->nr_maxactive;
>  	else
> -		size = num * num_possible_cpus() * 2;
> -	if (size <= 0)
> +		num *= num_possible_cpus() * 2;
> +	if (num <= 0)
>  		return -EINVAL;
>  
> +	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
> +
>  	/* Initialize rethook */
> -	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
> -				sizeof(struct fprobe_rethook_node), size);
> +	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
>  	if (IS_ERR(fp->rethook))
>  		return PTR_ERR(fp->rethook);
>  
> 
>
Jiri Olsa Feb. 29, 2024, 9:58 p.m. UTC | #2 
On Thu, Feb 29, 2024 at 08:22:47PM +0900, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Fix to allocate fprobe::entry_data_size buffer with rethook instances.
> If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
> fprobe entry handler can cause a buffer overrun when storing entry data in
> entry handler.
> 
> Reported-by: Jiri Olsa <olsajiri@gmail.com>

Tested-by: Jiri Olsa <olsajiri@gmail.com>

thanks,
jirka

> Fixes: 4bbd93455659 ("kprobes: kretprobe scalability improvement")
> Cc: stable@vger.kernel.org
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  kernel/trace/fprobe.c |   14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index 6cd2a4e3afb8..9ff018245840 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
>  {
>  	int size;
>  
> -	if (num <= 0)
> -		return -EINVAL;
> -
>  	if (!fp->exit_handler) {
>  		fp->rethook = NULL;
>  		return 0;
> @@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
>  
>  	/* Initialize rethook if needed */
>  	if (fp->nr_maxactive)
> -		size = fp->nr_maxactive;
> +		num = fp->nr_maxactive;
>  	else
> -		size = num * num_possible_cpus() * 2;
> -	if (size <= 0)
> +		num *= num_possible_cpus() * 2;
> +	if (num <= 0)
>  		return -EINVAL;
>  
> +	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
> +
>  	/* Initialize rethook */
> -	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
> -				sizeof(struct fprobe_rethook_node), size);
> +	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
>  	if (IS_ERR(fp->rethook))
>  		return PTR_ERR(fp->rethook);
>  
>
Masami Hiramatsu (Google) Feb. 29, 2024, 10:50 p.m. UTC | #3 
On Thu, 29 Feb 2024 22:58:54 +0100
Jiri Olsa <olsajiri@gmail.com> wrote:

> On Thu, Feb 29, 2024 at 08:22:47PM +0900, Masami Hiramatsu (Google) wrote:
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > 
> > Fix to allocate fprobe::entry_data_size buffer with rethook instances.
> > If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
> > fprobe entry handler can cause a buffer overrun when storing entry data in
> > entry handler.
> > 
> > Reported-by: Jiri Olsa <olsajiri@gmail.com>
> 
> Tested-by: Jiri Olsa <olsajiri@gmail.com>

Thanks for testing!
Let me pick this to probe/fixes.

Thank you,

> 
> thanks,
> jirka
> 
> > Fixes: 4bbd93455659 ("kprobes: kretprobe scalability improvement")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > ---
> >  kernel/trace/fprobe.c |   14 ++++++--------
> >  1 file changed, 6 insertions(+), 8 deletions(-)
> > 
> > diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> > index 6cd2a4e3afb8..9ff018245840 100644
> > --- a/kernel/trace/fprobe.c
> > +++ b/kernel/trace/fprobe.c
> > @@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
> >  {
> >  	int size;
> >  
> > -	if (num <= 0)
> > -		return -EINVAL;
> > -
> >  	if (!fp->exit_handler) {
> >  		fp->rethook = NULL;
> >  		return 0;
> > @@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
> >  
> >  	/* Initialize rethook if needed */
> >  	if (fp->nr_maxactive)
> > -		size = fp->nr_maxactive;
> > +		num = fp->nr_maxactive;
> >  	else
> > -		size = num * num_possible_cpus() * 2;
> > -	if (size <= 0)
> > +		num *= num_possible_cpus() * 2;
> > +	if (num <= 0)
> >  		return -EINVAL;
> >  
> > +	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
> > +
> >  	/* Initialize rethook */
> > -	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
> > -				sizeof(struct fprobe_rethook_node), size);
> > +	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
> >  	if (IS_ERR(fp->rethook))
> >  		return PTR_ERR(fp->rethook);
> >  
> >
diff mbox series

Patch

diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 6cd2a4e3afb8..9ff018245840 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -189,9 +189,6 @@  static int fprobe_init_rethook(struct fprobe *fp, int num)
 {
 	int size;
 
-	if (num <= 0)
-		return -EINVAL;
-
 	if (!fp->exit_handler) {
 		fp->rethook = NULL;
 		return 0;
@@ -199,15 +196,16 @@  static int fprobe_init_rethook(struct fprobe *fp, int num)
 
 	/* Initialize rethook if needed */
 	if (fp->nr_maxactive)
-		size = fp->nr_maxactive;
+		num = fp->nr_maxactive;
 	else
-		size = num * num_possible_cpus() * 2;
-	if (size <= 0)
+		num *= num_possible_cpus() * 2;
+	if (num <= 0)
 		return -EINVAL;
 
+	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
+
 	/* Initialize rethook */
-	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
-				sizeof(struct fprobe_rethook_node), size);
+	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
 	if (IS_ERR(fp->rethook))
 		return PTR_ERR(fp->rethook);