| Message ID | 20240403131518.61392-2-warthog618@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] gpio: cdev: fix missed label sanitizing in debounce_setup() | expand |
On Thu, Apr 04, 2024 at 10:20:29AM +0200, Bartosz Golaszewski wrote: > On Wed, Apr 3, 2024 at 3:15 PM Kent Gibson <warthog618@gmail.com> wrote: > > > > When adding sanitization of the label, the path through > > edge_detector_setup() that leads to debounce_setup() was overlooked. > > A request taking this path does not allocate a new label and the > > request label is freed twice when the request is released, resulting > > in memory corruption. > > > > Add label sanitization to debounce_setup(). > > > > Cc: stable@vger.kernel.org > > Fixes: b34490879baa ("gpio: cdev: sanitize the label before requesting the interrupt") > > Signed-off-by: Kent Gibson <warthog618@gmail.com> > > --- > > drivers/gpio/gpiolib-cdev.c | 31 +++++++++++++++++++------------ > > 1 file changed, 19 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c > > index fa9635610251..f4c2da2041e5 100644 > > --- a/drivers/gpio/gpiolib-cdev.c > > +++ b/drivers/gpio/gpiolib-cdev.c > > @@ -728,6 +728,16 @@ static u32 line_event_id(int level) > > GPIO_V2_LINE_EVENT_FALLING_EDGE; > > } > > > > +static inline char *make_irq_label(const char *orig) > > +{ > > + return kstrdup_and_replace(orig, '/', ':', GFP_KERNEL); > > +} > > + > > +static inline void free_irq_label(const char *label) > > +{ > > + kfree(label); > > +} > > + > > #ifdef CONFIG_HTE > > > > static enum hte_return process_hw_ts_thread(void *p) > > @@ -1015,6 +1025,7 @@ static int debounce_setup(struct line *line, unsigned int debounce_period_us) > > { > > unsigned long irqflags; > > int ret, level, irq; > > + char *label; > > > > /* try hardware */ > > ret = gpiod_set_debounce(line->desc, debounce_period_us); > > @@ -1037,11 +1048,17 @@ static int debounce_setup(struct line *line, unsigned int debounce_period_us) > > if (irq < 0) > > return -ENXIO; > > > > + label = make_irq_label(line->req->label); > > Now that I look at the actual patch, I don't really like it. We > introduce a bug just to fix it a commit later. Such things have been > frowned upon in the past. > > Let me shuffle the code a bit, I'll try to make it a bit more correct. > The debounce_setup() oversight bug is the more severe, so it makes more sense to me to fix it first. But then I my preferred solution would be to pull the original patch and submit a corrected patch that merges all three, so no bugs, but I assume that isn't an option. Cheers, Kent.
On Thu, Apr 4, 2024 at 12:59 PM Kent Gibson <warthog618@gmail.com> wrote: > > On Thu, Apr 04, 2024 at 10:20:29AM +0200, Bartosz Golaszewski wrote: > > > > Now that I look at the actual patch, I don't really like it. We > > introduce a bug just to fix it a commit later. Such things have been > > frowned upon in the past. > > > > Let me shuffle the code a bit, I'll try to make it a bit more correct. > > > > The debounce_setup() oversight bug is the more severe, so it makes more > sense to me to fix it first. But then I my preferred solution would be > to pull the original patch and submit a corrected patch that merges all > three, so no bugs, but I assume that isn't an option. > Nah, let's not needlessly rebase it. Most I can do is merge the two but they are really functionally separate so I'd keep it as is in v2. Bart
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index fa9635610251..f4c2da2041e5 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -728,6 +728,16 @@ static u32 line_event_id(int level) GPIO_V2_LINE_EVENT_FALLING_EDGE; } +static inline char *make_irq_label(const char *orig) +{ + return kstrdup_and_replace(orig, '/', ':', GFP_KERNEL); +} + +static inline void free_irq_label(const char *label) +{ + kfree(label); +} + #ifdef CONFIG_HTE static enum hte_return process_hw_ts_thread(void *p) @@ -1015,6 +1025,7 @@ static int debounce_setup(struct line *line, unsigned int debounce_period_us) { unsigned long irqflags; int ret, level, irq; + char *label; /* try hardware */ ret = gpiod_set_debounce(line->desc, debounce_period_us); @@ -1037,11 +1048,17 @@ static int debounce_setup(struct line *line, unsigned int debounce_period_us) if (irq < 0) return -ENXIO; + label = make_irq_label(line->req->label); + if (!label) + return -ENOMEM; + irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; ret = request_irq(irq, debounce_irq_handler, irqflags, - line->req->label, line); - if (ret) + label, line); + if (ret) { + free_irq_label(label); return ret; + } line->irq = irq; } else { ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH); @@ -1083,16 +1100,6 @@ static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, return 0; } -static inline char *make_irq_label(const char *orig) -{ - return kstrdup_and_replace(orig, '/', ':', GFP_KERNEL); -} - -static inline void free_irq_label(const char *label) -{ - kfree(label); -} - static void edge_detector_stop(struct line *line) { if (line->irq) {
When adding sanitization of the label, the path through edge_detector_setup() that leads to debounce_setup() was overlooked. A request taking this path does not allocate a new label and the request label is freed twice when the request is released, resulting in memory corruption. Add label sanitization to debounce_setup(). Cc: stable@vger.kernel.org Fixes: b34490879baa ("gpio: cdev: sanitize the label before requesting the interrupt") Signed-off-by: Kent Gibson <warthog618@gmail.com> --- drivers/gpio/gpiolib-cdev.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-)