| Message ID | 1572936379-6423-1-git-send-email-bianpan2016@163.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 79aae6acbef16f720a7949f8fc6ac69816c79d62 |
| Headers | show |
| Series | Input: cyttsp4_core: fix use after free bug | expand |
On Tue, Nov 05, 2019 at 02:46:19PM +0800, Pan Bian wrote: > The device md->input is used after it is released. Setting the device > data to NULL is unnecessary as the device is never used again. Instead, > md->input should be assigned NULL to avoid accessing the freed memory > accidently. No, we are tearing up the device anyway, I'd leave it as it was, so I'll drop this chunk and apply the rest. Thank you.
diff --git a/drivers/input/touchscreen/cyttsp4_core.c b/drivers/input/touchscreen/cyttsp4_core.c index 4b22d49a0f49..2cd5f835665e 100644 --- a/drivers/input/touchscreen/cyttsp4_core.c +++ b/drivers/input/touchscreen/cyttsp4_core.c @@ -1990,11 +1990,6 @@ static int cyttsp4_mt_probe(struct cyttsp4 *cd) /* get sysinfo */ md->si = &cd->sysinfo; - if (!md->si) { - dev_err(dev, "%s: Fail get sysinfo pointer from core p=%p\n", - __func__, md->si); - goto error_get_sysinfo; - } rc = cyttsp4_setup_input_device(cd); if (rc) @@ -2004,8 +1999,7 @@ static int cyttsp4_mt_probe(struct cyttsp4 *cd) error_init_input: input_free_device(md->input); -error_get_sysinfo: - input_set_drvdata(md->input, NULL); + md->input = NULL; error_alloc_failed: dev_err(dev, "%s failed.\n", __func__); return rc;
The device md->input is used after it is released. Setting the device data to NULL is unnecessary as the device is never used again. Instead, md->input should be assigned NULL to avoid accessing the freed memory accidently. Besides, checking md->si against NULL is superfluous as it points to a variable address, which cannot be NULL. Signed-off-by: Pan Bian <bianpan2016@163.com> --- drivers/input/touchscreen/cyttsp4_core.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)