Messages in this thread Patch in this message | | | From | Luiz Sampaio <> | Subject | [PATCH 2/2] auxdisplay: charlcd: checking for pointer reference before dereferencing | Date | Sun, 7 Nov 2021 12:03:04 -0300 |
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Check if the pointer lcd->ops->init_display exists before dereferencing it. If a driver called charlcd_init() without defining the ops, this would return segmentation fault, as happened to me when implementing a charlcd driver. Checking the pointer before dereferencing protects from segmentation fault.
Signed-off-by: Luiz Sampaio <sampaio.ime@gmail.com> --- drivers/auxdisplay/charlcd.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index cca3b600c0ba..47363fb2fe94 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -578,6 +578,9 @@ static int charlcd_init(struct charlcd *lcd) * Since charlcd_init_display() needs to write data, we have to * enable mark the LCD initialized just before. */ + if (!lcd->ops->init_display) + return -EFAULT; + ret = lcd->ops->init_display(lcd); if (ret) return ret; -- 2.33.1
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