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: [email protected]
Signed-off-by: Krishna chaitanya chundru <[email protected]>
---
Changes in v2:
- Change the modulus operation to bit-wise & operation as suggested by Jeff.
- Link to v1: https://lore.kernel.org/r/[email protected]
---
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 <[email protected]>
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: [email protected]
> Signed-off-by: Krishna chaitanya chundru <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Bjorn gave his R-b tag for v1 and you didn't include it. If you dropped it on
purpose, then you should mention it in the "Changes" along with a justification.
- Mani
> ---
> Changes in v2:
> - Change the modulus operation to bit-wise & operation as suggested by Jeff.
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> 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 <[email protected]>
>
--
மணிவண்ணன் சதாசிவம்
On 11/1/2023 10:47 AM, Manivannan Sadhasivam wrote:
> 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: [email protected]
>> Signed-off-by: Krishna chaitanya chundru <[email protected]>
> Reviewed-by: Manivannan Sadhasivam <[email protected]>
>
> Bjorn gave his R-b tag for v1 and you didn't include it. If you dropped it on
> purpose, then you should mention it in the "Changes" along with a justification.
>
> - Mani
As there is change in the logic I didn't include the tag. I will mention
this on the next patch.
- Krishna Chaitanya.
>> ---
>> Changes in v2:
>> - Change the modulus operation to bit-wise & operation as suggested by Jeff.
>> - Link to v1: https://lore.kernel.org/r/[email protected]
>> ---
>> 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 <[email protected]>
>>
On 10/31/2023 3:51 AM, 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: [email protected]
> Signed-off-by: Krishna chaitanya chundru <[email protected]>
Reviewed-by: Jeffrey Hugo <[email protected]>
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: [email protected]
> Signed-off-by: Krishna chaitanya chundru <[email protected]>
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/[email protected]
> ---
> 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 <[email protected]>
>
>
--
மணிவண்ணன் சதாசிவம்