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| author | Luiz Sampaio <sampaio.ime@gmail.com> | 2021-11-10 01:07:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-11 17:35:17 +0300 |
| commit | 4ed66cdc542fdb948d67f2254fdac4106786a76e (patch) | |
| tree | e8ec086e6cbcf51c8bf4f3ca2108a07b937d7a7a /drivers/auxdisplay | |
| parent | 8a7520c49994ab1d43221e6445252e9fad0b3391 (diff) | |
| download | linux-4ed66cdc542fdb948d67f2254fdac4106786a76e.tar.xz | |
auxdisplay: charlcd: checking for pointer reference before dereferencing
[ Upstream commit 4daa9ff89ef27be43c15995412d6aee393a78200 ]
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>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/auxdisplay')
| -rw-r--r-- | drivers/auxdisplay/charlcd.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index 304accde365c..6c010d4efa4a 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 (WARN_ON(!lcd->ops->init_display)) + return -EINVAL; + ret = lcd->ops->init_display(lcd); if (ret) return ret; |