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gpio: cdev: check for NULL labels when sanitizing them for irqs

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commit b3b95964590a3d756d69ea8604c856de805479ad upstream.

We need to take into account that a line's consumer label may be NULL
and not try to kstrdup() it in that case but rather pass the NULL
pointer up the stack to the interrupt request function.

To that end: let make_irq_label() return NULL as a valid return value
and use ERR_PTR() instead to signal an allocation failure to callers.

Cc: stable@vger.kernel.org
Fixes: b34490879baa ("gpio: cdev: sanitize the label before requesting the interrupt")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/lkml/20240402093534.212283-1-naresh.kamboju@linaro.org/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bartosz Golaszewski 2024-04-04 11:33:27 +02:00 committed by Greg Kroah-Hartman
parent 63bd08629a
commit d9f0804ab0
1 changed files with 14 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/gpio/gpiolib-cdev.c
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@ -1012,7 +1012,16 @@ static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc,
static inline char *make_irq_label(const char *orig)
{
return kstrdup_and_replace(orig, '/', ':', GFP_KERNEL);
char *new;
if (!orig)
return NULL;
new = kstrdup_and_replace(orig, '/', ':', GFP_KERNEL);
if (!new)
return ERR_PTR(-ENOMEM);
return new;
}
static inline void free_irq_label(const char *label)
@ -1086,8 +1095,8 @@ static int edge_detector_setup(struct line *line,
irqflags |= IRQF_ONESHOT;
label = make_irq_label(line->req->label);
if (!label)
return -ENOMEM;
if (IS_ERR(label))
return PTR_ERR(label);
/* Request a thread to read the events */
ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread,
@ -2194,8 +2203,8 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
goto out_free_le;
label = make_irq_label(le->label);
if (!label) {
ret = -ENOMEM;
if (IS_ERR(label)) {
ret = PTR_ERR(label);
goto out_free_le;
}