From: Cristian Marussi cristian.marussi@arm.com

[ Upstream commit e9076ffbcaed5da6c182b144ef9f6e24554af268 ]

Accessing reset domains descriptors by the index upon the SCMI drivers requests through the SCMI reset operations interface can potentially lead to out-of-bound violations if the SCMI driver misbehave.

Add an internal consistency check before any such domains descriptors accesses.

Link: https://lore.kernel.org/r/20220817172731.1185305-5-cristian.marussi@arm.com Signed-off-by: Cristian Marussi cristian.marussi@arm.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com Signed-off-by: Dominique Martinet dominique.martinet@atmark-techno.com --- This is the backport I promised for CVE-2022-48655[1] [1] https://lkml.kernel.org/r/Zj4t4q_w6gqzdvhz@codewreck.org

The 'pi' variable declaration context just changed a bit (handle->reset_priv -> ph->get_priv(ph)) but the patch is otherwise fine as is. (I've also checked that num_domains is properly initialized at module init time and this part of the code hasn't changed until 5.15, so it should be safe to use this previously unused field)

This same patch applies cleanly to both 5.4.275 and 5.10.216.

Thanks!

drivers/firmware/arm_scmi/reset.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c index a981a22cfe89..b8388a3b9c06 100644 --- a/drivers/firmware/arm_scmi/reset.c +++ b/drivers/firmware/arm_scmi/reset.c @@ -149,8 +149,12 @@ static int scmi_domain_reset(const struct scmi_handle *handle, u32 domain, struct scmi_xfer *t; struct scmi_msg_reset_domain_reset *dom; struct scmi_reset_info *pi = handle->reset_priv; - struct reset_dom_info *rdom = pi->dom_info + domain; + struct reset_dom_info *rdom;

+ if (domain >= pi->num_domains) + return -EINVAL; + + rdom = pi->dom_info + domain; if (rdom->async_reset) flags |= ASYNCHRONOUS_RESET;