Re: [PATCH 1/2] soc: qcom: smem: add boundary checks for partitions

[Deepak Kumar Singh <deepak.singh@oss.qualcomm.com>]

On 9/1/2026 12:34 PM, Albert Esteve wrote:
> On Tue, Sep 1, 2026 at 12:54 AM Bjorn Andersson <andersson@kernel.org> wrote:
>> On Thu, Aug 20, 2026 at 01:34:18PM +0200, Albert Esteve wrote:
>>> From: Sudeepgoud Patil <quic_sudeepgo@quicinc.com>
>>>
>>> Add condition check to make sure that the end address
>>> of private entry does not go out of partition.
>>>
>>> Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
>>> Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@quicinc.com>
>>> Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@quicinc.com>
>>> Signed-off-by: Albert Esteve <aesteve@redhat.com>
>> I'm sorry, Albert. Sudeepgoud messed up the authorship vs signed-off-by
>> chain here. The author should be "Sarannya", as that's the first
>> signed-off-by.
>>
>> PS. It would also be nice if this was submitted with updated email
>> addresses and copyright statement. But I'd not expect you to fix that.
> Hi Bjorn,
>
> I'm happy to address these changes for V2. Do you know where to find
> the updated email addresses?
>
> BR,
> Albert.

Hi Albert,

Sorry for providing this info late. In case you post new series please use below ids-

Sarannya S <sarannya.s@oss.qualcomm.com>
Pranav Mahesh Phansalkar <pranav.phansalkar@oss.qualcomm.com>
Tony Truong <tony.truong@oss.qualcomm.com>
Sudeepgoud Patil <sudeep.patil@oss.qualcomm.com>

Regards,
Deepak

>
>> Regards,
>> Bjorn
>>
>>> ---
>>>   drivers/soc/qcom/smem.c | 105 +++++++++++++++++++++++++++++++++---------------
>>>   1 file changed, 72 insertions(+), 33 deletions(-)
>>>
>>> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
>>> index afb21a778fe7b..194ffb2ac010f 100644
>>> --- a/drivers/soc/qcom/smem.c
>>> +++ b/drivers/soc/qcom/smem.c
>>> @@ -2,6 +2,7 @@
>>>   /*
>>>    * Copyright (c) 2015, Sony Mobile Communications AB.
>>>    * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
>>> + * Copyright (c) 2023-2024 Qualcomm Innovation Center, Inc. All rights reserved.
>>>    */
>>>
>>>   #include <linux/hwspinlock.h>
>>> @@ -85,6 +86,17 @@
>>>   /* Processor/host identifier for the global partition */
>>>   #define SMEM_GLOBAL_HOST     0xfffe
>>>
>>> +/* Entry range check
>>> + * ptr >= start : Checks if ptr is greater than the start of access region
>>> + * ptr + size >= ptr: Check for integer overflow (On 32bit system where ptr
>>> + * and size are 32bits, ptr + size can wrap around to be a small integer)
>>> + * ptr + size <= end: Checks if ptr+size is less than the end of access region
>>> + */
>>> +#define IN_PARTITION_RANGE(ptr, size, start, end)            \
>>> +     (((void *)(ptr) >= (void *)(start)) &&                  \
>>> +      (((void *)(ptr) + (size)) >= (void *)(ptr)) && \
>>> +      (((void *)(ptr) + (size)) <= (void *)(end)))
>>> +
>>>   /**
>>>     * struct smem_proc_comm - proc_comm communication struct (legacy)
>>>     * @command:        current command to be executed
>>> @@ -403,6 +415,7 @@ static int qcom_smem_alloc_private(struct qcom_smem *smem,
>>>                                   size_t size)
>>>   {
>>>        struct smem_private_entry *hdr, *end;
>>> +     struct smem_private_entry *next_hdr;
>>>        struct smem_partition_header *phdr;
>>>        size_t alloc_size;
>>>        void *cached;
>>> @@ -415,19 +428,25 @@ static int qcom_smem_alloc_private(struct qcom_smem *smem,
>>>        end = phdr_to_last_uncached_entry(phdr);
>>>        cached = phdr_to_last_cached_entry(phdr);
>>>
>>> -     if (WARN_ON((void *)end > p_end || cached > p_end))
>>> +     if (WARN_ON(!IN_PARTITION_RANGE(end, 0, phdr, cached) ||
>>> +                                             cached > p_end))
>>>                return -EINVAL;
>>>
>>> -     while (hdr < end) {
>>> +     while ((hdr < end) && ((hdr + 1) < end)) {
>>>                if (hdr->canary != SMEM_PRIVATE_CANARY)
>>>                        goto bad_canary;
>>>                if (le16_to_cpu(hdr->item) == item)
>>>                        return -EEXIST;
>>>
>>> -             hdr = uncached_entry_next(hdr);
>>> +             next_hdr = uncached_entry_next(hdr);
>>> +
>>> +             if (WARN_ON(next_hdr <= hdr))
>>> +                     return -EINVAL;
>>> +
>>> +             hdr = next_hdr;
>>>        }
>>>
>>> -     if (WARN_ON((void *)hdr > p_end))
>>> +     if (WARN_ON((void *)hdr > (void *)end))
>>>                return -EINVAL;
>>>
>>>        /* Check that we don't grow into the cached region */
>>> @@ -587,9 +606,11 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
>>>                                   unsigned item,
>>>                                   size_t *size)
>>>   {
>>> -     struct smem_private_entry *e, *end;
>>> +     struct smem_private_entry *e, *uncached_end, *cached_end;
>>> +     struct smem_private_entry *next_e;
>>>        struct smem_partition_header *phdr;
>>>        void *item_ptr, *p_end;
>>> +     size_t entry_size = 0;
>>>        u32 padding_data;
>>>        u32 e_size;
>>>
>>> @@ -597,67 +618,85 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
>>>        p_end = (void *)phdr + part->size;
>>>
>>>        e = phdr_to_first_uncached_entry(phdr);
>>> -     end = phdr_to_last_uncached_entry(phdr);
>>> +     uncached_end = phdr_to_last_uncached_entry(phdr);
>>> +     cached_end = phdr_to_last_cached_entry(phdr);
>>> +
>>> +     if (WARN_ON(!IN_PARTITION_RANGE(uncached_end, 0, phdr, cached_end)
>>> +                                     || (void *)cached_end > p_end))
>>> +             return ERR_PTR(-EINVAL);
>>>
>>> -     while (e < end) {
>>> +     while ((e < uncached_end) && ((e + 1) < uncached_end)) {
>>>                if (e->canary != SMEM_PRIVATE_CANARY)
>>>                        goto invalid_canary;
>>>
>>>                if (le16_to_cpu(e->item) == item) {
>>> -                     if (size != NULL) {
>>> -                             e_size = le32_to_cpu(e->size);
>>> -                             padding_data = le16_to_cpu(e->padding_data);
>>> +                     e_size = le32_to_cpu(e->size);
>>> +                     padding_data = le16_to_cpu(e->padding_data);
>>>
>>> -                             if (WARN_ON(e_size > part->size || padding_data > e_size))
>>> -                                     return ERR_PTR(-EINVAL);
>>> +                     if (e_size < part->size && padding_data < e_size)
>>> +                             entry_size = e_size - padding_data;
>>> +                     else
>>> +                             return ERR_PTR(-EINVAL);
>>>
>>> -                             *size = e_size - padding_data;
>>> -                     }
>>> +                     item_ptr =  uncached_entry_to_item(e);
>>>
>>> -                     item_ptr = uncached_entry_to_item(e);
>>> -                     if (WARN_ON(item_ptr > p_end))
>>> +                     if (WARN_ON(!IN_PARTITION_RANGE(item_ptr, entry_size, e, uncached_end)))
>>>                                return ERR_PTR(-EINVAL);
>>>
>>> +                     if (size != NULL)
>>> +                             *size = entry_size;
>>> +
>>>                        return item_ptr;
>>>                }
>>>
>>> -             e = uncached_entry_next(e);
>>> -     }
>>> +             next_e = uncached_entry_next(e);
>>> +             if (WARN_ON(next_e <= e))
>>> +                     return ERR_PTR(-EINVAL);
>>>
>>> -     if (WARN_ON((void *)e > p_end))
>>> +             e = next_e;
>>> +     }
>>> +     if (WARN_ON((void *)e > (void *)uncached_end))
>>>                return ERR_PTR(-EINVAL);
>>>
>>>        /* Item was not found in the uncached list, search the cached list */
>>>
>>> +     if (cached_end == p_end)
>>> +             return ERR_PTR(-ENOENT);
>>> +
>>>        e = phdr_to_first_cached_entry(phdr, part->cacheline);
>>> -     end = phdr_to_last_cached_entry(phdr);
>>>
>>> -     if (WARN_ON((void *)e < (void *)phdr || (void *)end > p_end))
>>> +     if (WARN_ON(!IN_PARTITION_RANGE(cached_end, 0, uncached_end, p_end) ||
>>> +                     !IN_PARTITION_RANGE(e, sizeof(*e), cached_end, p_end)))
>>>                return ERR_PTR(-EINVAL);
>>>
>>> -     while (e > end) {
>>> +     while (e > cached_end) {
>>>                if (e->canary != SMEM_PRIVATE_CANARY)
>>>                        goto invalid_canary;
>>>
>>>                if (le16_to_cpu(e->item) == item) {
>>> -                     if (size != NULL) {
>>> -                             e_size = le32_to_cpu(e->size);
>>> -                             padding_data = le16_to_cpu(e->padding_data);
>>> +                     e_size = le32_to_cpu(e->size);
>>> +                     padding_data = le16_to_cpu(e->padding_data);
>>>
>>> -                             if (WARN_ON(e_size > part->size || padding_data > e_size))
>>> -                                     return ERR_PTR(-EINVAL);
>>> -
>>> -                             *size = e_size - padding_data;
>>> -                     }
>>> +                     if (e_size < part->size && padding_data < e_size)
>>> +                             entry_size  = e_size - padding_data;
>>> +                     else
>>> +                             return ERR_PTR(-EINVAL);
>>>
>>> -                     item_ptr = cached_entry_to_item(e);
>>> -                     if (WARN_ON(item_ptr < (void *)phdr))
>>> +                     item_ptr =  cached_entry_to_item(e);
>>> +                     if (WARN_ON(!IN_PARTITION_RANGE(item_ptr, entry_size, cached_end, e)))
>>>                                return ERR_PTR(-EINVAL);
>>>
>>> +                     if (size != NULL)
>>> +                             *size = entry_size;
>>> +
>>>                        return item_ptr;
>>>                }
>>>
>>> -             e = cached_entry_next(e, part->cacheline);
>>> +             next_e = cached_entry_next(e, part->cacheline);
>>> +             if (WARN_ON(next_e >= e))
>>> +                     return ERR_PTR(-EINVAL);
>>> +
>>> +             e = next_e;
>>>        }
>>>
>>>        if (WARN_ON((void *)e < (void *)phdr))
>>>
>>> --
>>> 2.55.0
>>>