forge/linux-uconsole
1
0
Fork 0
Code Issues 1 Pull requests Projects Releases Packages Wiki Activity Actions

firmware: arm_scmi: Harden shared memory access in fetch_notification

Browse source 
[ Upstream commit 9bae076cd4 ]

A misbheaving SCMI platform firmware could reply with out-of-spec
notifications, shorter than the mimimum size comprising a header.

Fixes: d5141f37c4 ("firmware: arm_scmi: Add notifications support in transport layer")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222183823.518856-4-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Cristian Marussi 2022-12-22 18:38:21 +00:00 • committed by Greg Kroah-Hartman
commit 6813d8ba7d
1 changed files with 3 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

4
drivers/firmware/arm_scmi/shmem.c
View file

@ -71,8 +71,10 @@ void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
size_t max_len, struct scmi_xfer *xfer)
{
size_t len = ioread32(&shmem->length);
/* Skip only the length of header in shmem area i.e 4 bytes */
xfer->rx.len = min_t(size_t, max_len, ioread32(&shmem->length) - 4);
xfer->rx.len = min_t(size_t, max_len, len > 4 ? len - 4 : 0);
/* Take a copy to the rx buffer.. */
memcpy_fromio(xfer->rx.buf, shmem->msg_payload, xfer->rx.len);