5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
[ Upstream commit eff9704f5332a13b08fbdbe0f84059c9e7051d5f ]
Though we do check the event ring read pointer by "is_valid_ring_ptr"
to make sure it is in the buffer range, but there is another risk the
pointer may be not aligned. Since we are expecting event ring elements
are 128 bits(struct mhi_ring_element) aligned, an unaligned read pointer
could lead to multiple issues like DoS or ring buffer memory corruption.
So add a alignment check for event ring read pointer.
Fixes: ec32332df764 ("bus: mhi: core: Sanity check values from remote device before use")
cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
Reviewed-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231031-alignment_check-v2-1-1441db7c5efd@xxxxxxxxxxx
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/bus/mhi/host/main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index 23bd1db94558..1cb7c60594f1 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -267,7 +267,8 @@ static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl,
static bool is_valid_ring_ptr(struct mhi_ring *ring, dma_addr_t addr)
{
- return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len;
+ return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len &&
+ !(addr & (sizeof(struct mhi_ring_element) - 1));
}
int mhi_destroy_device(struct device *dev, void *data)
--
2.43.0
