FROMGIT firmware: qcom: scm: fix a NULL-pointer dereference

Bartosz Golaszewski · z3ntu · commit 44aa81907252 · 2024-10-20T14:43:25.000+02:00
Some SCM calls can be invoked with __scm being NULL (the driver may not have been and will not be probed as there's no SCM entry in device-tree). Make sure we don't dereference a NULL pointer. Fixes: 449d0d8 ("firmware: qcom: scm: smc: switch to using the SCM allocator") Reported-by: Rudraksha Gupta <guptarud@gmail.com> Closes: https://lore.kernel.org/lkml/692cfe9a-8c05-4ce4-813e-82b3f310019a@gmail.com/ Reviewed-by: Konrad Dybcio <konradybcio@kernel.org> Tested-by: Rudraksha Gupta <guptarud@gmail.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Reviewed-by: Stephan Gerhold <stephan.gerhold@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Kuldeep Singh <quic_kuldsing@quicinc.com> Link: https://lore.kernel.org/r/20240930083328.17904-1-brgl@bgdev.pl Signed-off-by: Bjorn Andersson <andersson@kernel.org> (cherry picked from commit ca61d68)
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
@@ -207,7 +207,7 @@ static DEFINE_SPINLOCK(scm_query_lock);
 
 struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void)
 {
-	return __scm->mempool;
+	return __scm ? __scm->mempool : NULL;
 }
 
 static enum qcom_scm_convention __get_convention(void)

Original file line number	Diff line number	Diff line change
`@@ -207,7 +207,7 @@ static DEFINE_SPINLOCK(scm_query_lock);`
`207`	`207`
`208`	`208`	`struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void)`
`209`	`209`	`{`
`210`		`- return __scm->mempool;`
	`210`	`+ return __scm ? __scm->mempool : NULL;`
`211`	`211`	`}`
`212`	`212`
`213`	`213`	`static enum qcom_scm_convention __get_convention(void)`