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Commit d3d2774d authored by Deepak Kumar Singh's avatar Deepak Kumar Singh
Browse files

soc: qcom: smem: validate fields of shared structures 



Structures in shared memory that can be modified by remote
processors may have untrusted values, they should be validated
before use.

Adding proper validation before using fields of shared
structures.

CRs-Fixed: 2421611
Change-Id: Ifed71c506a26105eac3db9ee35f086d7dbf5a3a3
Signed-off-by: default avatarDeepak Kumar Singh <deesin@codeaurora.org>
parent fec7194f

drivers/soc/qcom/smem.c

+129 −57
Original line number Diff line number Diff line
@@ -256,11 +256,9 @@ struct smem_region { 
 * struct qcom_smem - device data for the smem device

 * @dev:	device pointer

 * @hwlock:	reference to a hwspinlock

 * @global_partition:	pointer to global partition when in use

 * @global_cacheline:	cacheline size for global partition

 * @partitions:	list of pointers to partitions affecting the current

 * @global_partition_entry: pointer to global partition entry when in use

 * @ptable_entries: list of pointers to partitions table entry of current

 *		processor/host

 * @cacheline:	list of cacheline sizes for each host

 * @item_count: max accepted item number

 * @num_regions: number of @regions

 * @regions:	list of the memory regions defining the shared memory
@@ -270,16 +268,26 @@ struct qcom_smem { 


	struct hwspinlock *hwlock;



	struct smem_partition_header *global_partition;

	size_t global_cacheline;

	struct smem_partition_header *partitions[SMEM_HOST_COUNT];

	size_t cacheline[SMEM_HOST_COUNT];

	struct smem_ptable_entry *global_partition_entry;

	struct smem_ptable_entry *ptable_entries[SMEM_HOST_COUNT];

	u32 item_count;



	unsigned num_regions;

	struct smem_region regions[0];

};



/* Pointer to the one and only smem handle */

static struct qcom_smem *__smem;



/* Timeout (ms) for the trylock of remote spinlocks */

#define HWSPINLOCK_TIMEOUT	1000



static struct smem_partition_header *

ptable_entry_to_phdr(struct smem_ptable_entry *entry)

{

	return __smem->regions[0].virt_base + le32_to_cpu(entry->offset);

}



static struct smem_private_entry *

phdr_to_last_uncached_entry(struct smem_partition_header *phdr)

{
@@ -342,25 +350,27 @@ static void *cached_entry_to_item(struct smem_private_entry *e) 
	return p - le32_to_cpu(e->size);

}



/* Pointer to the one and only smem handle */

static struct qcom_smem *__smem;



/* Timeout (ms) for the trylock of remote spinlocks */

#define HWSPINLOCK_TIMEOUT	1000



static int qcom_smem_alloc_private(struct qcom_smem *smem,

				   struct smem_partition_header *phdr,

				   struct smem_ptable_entry *entry,

				   unsigned item,

				   size_t size)

{

	struct smem_private_entry *hdr, *end;

	struct smem_partition_header *phdr;

	size_t alloc_size;

	void *cached;

	void *p_end;



	phdr = ptable_entry_to_phdr(entry);

	p_end = (void *)phdr + le32_to_cpu(entry->size);



	hdr = phdr_to_first_uncached_entry(phdr);

	end = phdr_to_last_uncached_entry(phdr);

	cached = phdr_to_last_cached_entry(phdr);



	if (WARN_ON((void *)end > p_end || (void *)cached > p_end))

		return -EINVAL;



	while (hdr < end) {

		if (hdr->canary != SMEM_PRIVATE_CANARY) {

			dev_err(smem->dev,
@@ -374,6 +384,8 @@ static int qcom_smem_alloc_private(struct qcom_smem *smem, 


		hdr = uncached_entry_next(hdr);

	}

	if (WARN_ON((void *)hdr > p_end))

		return -EINVAL;



	/* Check that we don't grow into the cached region */

	alloc_size = sizeof(*hdr) + ALIGN(size, 8);
@@ -443,7 +455,7 @@ static int qcom_smem_alloc_global(struct qcom_smem *smem, 
 */

int qcom_smem_alloc(unsigned host, unsigned item, size_t size)

{

	struct smem_partition_header *phdr;

	struct smem_ptable_entry *entry;

	unsigned long flags;

	int ret;
@@ -465,12 +477,12 @@ int qcom_smem_alloc(unsigned host, unsigned item, size_t size) 
	if (ret)

		return ret;



	if (host < SMEM_HOST_COUNT && __smem->partitions[host]) {

		phdr = __smem->partitions[host];

		ret = qcom_smem_alloc_private(__smem, phdr, item, size);

	} else if (__smem->global_partition) {

		phdr = __smem->global_partition;

		ret = qcom_smem_alloc_private(__smem, phdr, item, size);

	if (host < SMEM_HOST_COUNT && __smem->ptable_entries[host]) {

		entry = __smem->ptable_entries[host];

		ret = qcom_smem_alloc_private(__smem, entry, item, size);

	} else if (__smem->global_partition_entry) {

		entry = __smem->global_partition_entry;

		ret = qcom_smem_alloc_private(__smem, entry, item, size);

	} else {

		ret = qcom_smem_alloc_global(__smem, item, size);

	}
@@ -485,9 +497,11 @@ static void *qcom_smem_get_global(struct qcom_smem *smem, 
				  unsigned item,

				  size_t *size)

{

	struct smem_global_entry *entry;

	struct smem_header *header;

	struct smem_region *area;

	struct smem_global_entry *entry;

	u64 entry_offset;

	u32 e_size;

	u32 aux_base;

	unsigned i;
@@ -502,9 +516,16 @@ static void *qcom_smem_get_global(struct qcom_smem *smem, 
		area = &smem->regions[i];



		if (area->aux_base == aux_base || !aux_base) {

			e_size = le32_to_cpu(entry->size);

			entry_offset = le32_to_cpu(entry->offset);



			if (WARN_ON(e_size + entry_offset > area->size))

				return ERR_PTR(-EINVAL);



			if (size != NULL)

				*size = le32_to_cpu(entry->size);

			return area->virt_base + le32_to_cpu(entry->offset);

				*size = e_size;



			return area->virt_base + entry_offset;

		}

	}
@@ -512,50 +533,92 @@ static void *qcom_smem_get_global(struct qcom_smem *smem, 
}



static void *qcom_smem_get_private(struct qcom_smem *smem,

				   struct smem_partition_header *phdr,

				   size_t cacheline,

				   struct smem_ptable_entry *entry,

				   unsigned item,

				   size_t *size)

{

	struct smem_private_entry *e, *end;

	struct smem_partition_header *phdr;

	void *item_ptr, *p_end;

	u32 partition_size;

	size_t cacheline;

	u32 padding_data;

	u32 e_size;



	phdr = ptable_entry_to_phdr(entry);

	partition_size = le32_to_cpu(entry->size);

	p_end = (void *)phdr + partition_size;

	cacheline = le32_to_cpu(entry->cacheline);



	e = phdr_to_first_uncached_entry(phdr);

	end = phdr_to_last_uncached_entry(phdr);



	if (WARN_ON((void *)end > p_end))

		return ERR_PTR(-EINVAL);



	while (e < end) {

		if (e->canary != SMEM_PRIVATE_CANARY)

			goto invalid_canary;



		if (le16_to_cpu(e->item) == item) {

			if (size != NULL)

				*size = le32_to_cpu(e->size) -

					le16_to_cpu(e->padding_data);

			if (size != NULL) {

				e_size = le32_to_cpu(e->size);

				padding_data = le16_to_cpu(e->padding_data);



				if (e_size < partition_size

				    && padding_data < e_size)

					*size = e_size - padding_data;

				else

					return ERR_PTR(-EINVAL);

			}



			item_ptr =  uncached_entry_to_item(e);

			if (WARN_ON(item_ptr > p_end))

				return ERR_PTR(-EINVAL);



			return uncached_entry_to_item(e);

			return item_ptr;

		}



		e = uncached_entry_next(e);

	}

	if (WARN_ON((void *)e > p_end))

		return ERR_PTR(-EINVAL);



	/* Item was not found in the uncached list, search the cached list */



	e = phdr_to_first_cached_entry(phdr, cacheline);

	end = phdr_to_last_cached_entry(phdr);



	if (WARN_ON((void *)e < (void *)phdr || (void *)end > p_end))

		return ERR_PTR(-EINVAL);



	while (e > end) {

		if (e->canary != SMEM_PRIVATE_CANARY)

			goto invalid_canary;



		if (le16_to_cpu(e->item) == item) {

			if (size != NULL)

				*size = le32_to_cpu(e->size) -

					le16_to_cpu(e->padding_data);

			if (size != NULL) {

				e_size = le32_to_cpu(e->size);

				padding_data = le16_to_cpu(e->padding_data);



				if (e_size < partition_size

				    && padding_data < e_size)

					*size = e_size - padding_data;

				else

					return ERR_PTR(-EINVAL);

			}



			item_ptr =  cached_entry_to_item(e);

			if (WARN_ON(item_ptr < (void *)phdr))

				return ERR_PTR(-EINVAL);



			return cached_entry_to_item(e);

			return item_ptr;

		}



		e = cached_entry_next(e, cacheline);

	}

	if (WARN_ON((void *)e < (void *)phdr))

		return ERR_PTR(-EINVAL);



	return ERR_PTR(-ENOENT);
@@ -577,9 +640,8 @@ static void *qcom_smem_get_private(struct qcom_smem *smem, 
 */

void *qcom_smem_get(unsigned host, unsigned item, size_t *size)

{

	struct smem_partition_header *phdr;

	struct smem_ptable_entry *entry;

	unsigned long flags;

	size_t cacheln;

	int ret;

	void *ptr = ERR_PTR(-EPROBE_DEFER);
@@ -595,14 +657,12 @@ void *qcom_smem_get(unsigned host, unsigned item, size_t *size) 
	if (ret)

		return ERR_PTR(ret);



	if (host < SMEM_HOST_COUNT && __smem->partitions[host]) {

		phdr = __smem->partitions[host];

		cacheln = __smem->cacheline[host];

		ptr = qcom_smem_get_private(__smem, phdr, cacheln, item, size);

	} else if (__smem->global_partition) {

		phdr = __smem->global_partition;

		cacheln = __smem->global_cacheline;

		ptr = qcom_smem_get_private(__smem, phdr, cacheln, item, size);

	if (host < SMEM_HOST_COUNT && __smem->ptable_entries[host]) {

		entry = __smem->ptable_entries[host];

		ptr = qcom_smem_get_private(__smem, entry, item, size);

	} else if (__smem->global_partition_entry) {

		entry = __smem->global_partition_entry;

		ptr = qcom_smem_get_private(__smem, entry, item, size);

	} else {

		ptr = qcom_smem_get_global(__smem, item, size);

	}
@@ -624,23 +684,37 @@ EXPORT_SYMBOL(qcom_smem_get); 
int qcom_smem_get_free_space(unsigned host)

{

	struct smem_partition_header *phdr;

	struct smem_ptable_entry *entry;

	struct smem_header *header;

	unsigned ret;



	if (!__smem)

		return -EPROBE_DEFER;



	if (host < SMEM_HOST_COUNT && __smem->partitions[host]) {

		phdr = __smem->partitions[host];

	if (host < SMEM_HOST_COUNT && __smem->ptable_entries[host]) {

		entry = __smem->ptable_entries[host];

		phdr = ptable_entry_to_phdr(entry);



		ret = le32_to_cpu(phdr->offset_free_cached) -

		      le32_to_cpu(phdr->offset_free_uncached);

	} else if (__smem->global_partition) {

		phdr = __smem->global_partition;



		if (ret > le32_to_cpu(entry->size))

			return -EINVAL;

	} else if (__smem->global_partition_entry) {

		entry = __smem->global_partition_entry;

		phdr = ptable_entry_to_phdr(entry);



		ret = le32_to_cpu(phdr->offset_free_cached) -

		      le32_to_cpu(phdr->offset_free_uncached);



		if (ret > le32_to_cpu(entry->size))

			return -EINVAL;

	} else {

		header = __smem->regions[0].virt_base;

		ret = le32_to_cpu(header->available);



		if (ret > __smem->regions[0].size)

			return -EINVAL;

	}



	return ret;
@@ -751,7 +825,7 @@ static int qcom_smem_set_global_partition(struct qcom_smem *smem) 
		return -EINVAL;

	}



	if (smem->global_partition) {

	if (smem->global_partition_entry) {

		dev_err(smem->dev, "Already found the global partition\n");

		return -EINVAL;

	}
@@ -782,8 +856,7 @@ static int qcom_smem_set_global_partition(struct qcom_smem *smem) 
		return -EINVAL;

	}



	smem->global_partition = header;

	smem->global_cacheline = le32_to_cpu(entry->cacheline);

	smem->global_partition_entry = entry;



	return 0;

}
@@ -828,7 +901,7 @@ static int qcom_smem_enumerate_partitions(struct qcom_smem *smem, 
			return -EINVAL;

		}



		if (smem->partitions[remote_host]) {

		if (smem->ptable_entries[remote_host]) {

			dev_err(smem->dev,

				"Already found a partition for host %d\n",

				remote_host);
@@ -870,8 +943,7 @@ static int qcom_smem_enumerate_partitions(struct qcom_smem *smem, 
			return -EINVAL;

		}



		smem->partitions[remote_host] = header;

		smem->cacheline[remote_host] = le32_to_cpu(entry->cacheline);

		smem->ptable_entries[remote_host] = entry;

	}



	return 0;