On Tue, Oct 31, 2023 at 03:21:05PM +0530, Krishna chaitanya chundru wrote:
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@vger.kernel.org Signed-off-by: Krishna chaitanya chundru quic_krichai@quicinc.com
Applied to mhi-next!
- Mani
Changes in v2:
- Change the modulus operation to bit-wise & operation as suggested by Jeff.
- Link to v1: https://lore.kernel.org/r/20231023-alignment_check-v1-1-2ca5716d5c15@quicinc...
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 499590437e9b..e765c16a99d1 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -268,7 +268,8 @@ 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)
base-commit: 71e68e182e382e951d6248bccc3c960dcec5a718 change-id: 20231013-alignment_check-c013f509d24a
Best regards,
Krishna chaitanya chundru quic_krichai@quicinc.com