[PATCH v3 0/4] Add automotive SMEM hardening for Qualcomm platforms

[PATCH v3 0/4] Add automotive SMEM hardening for Qualcomm platforms

[Albert Esteve]

The Qualcomm SMEM driver manages shared memory partitions used for
inter-processor communication on Qualcomm SoCs, including the
automotive SA8775P platform. Vendor trees carry additional validation
and partition-enumeration logic that is not yet present in master.

Patch 1 adds IN_PARTITION_RANGE() for pointer+size checks against a region.

Patch 2 adds bounds checks when walking private uncached and cached
entry lists.

Patch 3 validates item payload size and pointer once a matching entry is
found.

Patch 4 skips multi-remote-host partitions during enumeration. SMEM
now supports partitions involving more than one remote host, but the
driver does not implement that case yet.

The first three patches split the original vendor boundary-check change
so each class of condition can be reviewed on its own. All four are
based on public vendor patches from Qualcomm [1][2]. Adapted for
master. In particular:

 - Dropped the xarray partition rework, which is already present in
   master (79602b750b96c, "soc: qcom: smem: Switch partitions to
   xarray")

Built on master (Linux 7.3-rc4), and tested (prior to rebase, with
Linux 7.2.0-rc6+) on Qualcomm SA8775P Ride V3 board. SMEM platform device
binds and initializes successfully.

[1] https://git.codelinaro.org/clo/la/kernel/qcom/-/commit/3e521f2641c8f01f00fd74a088206942ce23d6d4
[2] https://git.codelinaro.org/clo/la/kernel/qcom/-/commit/842dd28b0276b3824a607e067b3c20e266bcf230

Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
Changes in v3:
- Rebased to v7.3-rc4
- Split the overflow/boundary patch into helper, list-walk, and payload
  validation patches
- Fixed qcom_smem_get_private() while loop condition
- Fixed indentations
- Link to v2: https://lore.kernel.org/r/20260904-port-smem-v2-0-bb497dd3c48b@redhat.com

Changes in v2:
- Update patch 1 authorship to Sarannya
- Update all emails from @quicinc.com to @oss.qualcomm.com
- Make smem.c copyright yearless
- Link to v1: https://lore.kernel.org/r/20260820-port-smem-v1-0-d19a45f583bf@redhat.com

---
Sarannya S (3):
      soc: qcom: smem: add IN_PARTITION_RANGE helper
      soc: qcom: smem: validate private entry list walks
      soc: qcom: smem: validate private item payloads

Tony Truong (1):
      soc: qcom: smem: ignore multi remote host partitions

 drivers/soc/qcom/smem.c | 107 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 76 insertions(+), 31 deletions(-)
---
base-commit: 62f4c998b297cf233997a2b4cd6fc2d2df0319c9
change-id: 20260819-port-smem-7518c77c9415

Best regards,
-- 
Albert Esteve <aesteve@redhat.com>

[PATCH v3 1/4] soc: qcom: smem: add IN_PARTITION_RANGE helper

[Albert Esteve]

From: Sarannya S <quic_sarannya@oss.qualcomm.com>

Add IN_PARTITION_RANGE() to test that a pointer lies in [start, end]
and that pointer + size does not wrap.

Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 drivers/soc/qcom/smem.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index b5e7bd8c1512..6783a3c533f0 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) Qualcomm Technologies, Inc. and/or its subsidiaries.
  */
 
 #include <linux/debugfs.h>
@@ -88,6 +89,17 @@
 /* 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

-- 
2.55.0

[PATCH v3 2/4] soc: qcom: smem: validate private entry list walks

[Albert Esteve]

From: Sarannya S <quic_sarannya@oss.qualcomm.com>

When walking private entries, use the uncached/cached free offsets as
the list bounds, require room for a header before dereferencing, and
reject a next pointer that does not advance.

Skip the cached list when the cached free offset is at the partition
end.

Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 drivers/soc/qcom/smem.c | 50 ++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 13 deletions(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 6783a3c533f0..9bf0ec32c9f1 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -421,6 +421,7 @@ 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;
@@ -433,19 +434,25 @@ 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 + 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 */
@@ -604,7 +611,8 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 				   unsigned int 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;
 	u32 padding_data;
@@ -614,9 +622,14 @@ 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 + 1) < uncached_end) {
 		if (e->canary != SMEM_PRIVATE_CANARY)
 			goto invalid_canary;
 
@@ -638,21 +651,28 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 			return item_ptr;
 		}
 
-		e = uncached_entry_next(e);
+		next_e = uncached_entry_next(e);
+		if (WARN_ON(next_e <= e))
+			return ERR_PTR(-EINVAL);
+
+		e = next_e;
 	}
 
-	if (WARN_ON((void *)e > p_end))
+	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;
 
@@ -674,7 +694,11 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 			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

[PATCH v3 3/4] soc: qcom: smem: validate private item payloads

[Albert Esteve]

From: Sarannya S <quic_sarannya@oss.qualcomm.com>

Validate a matching entry's size and padding even when the caller does
not request the length, and check that the payload stays inside the
same region as the header.

Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 drivers/soc/qcom/smem.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 9bf0ec32c9f1..393257cbe5e1 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -615,6 +615,7 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 	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;
 
@@ -634,20 +635,21 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 			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 = 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;
 		}
 
@@ -677,20 +679,21 @@ static void *qcom_smem_get_private(struct qcom_smem *smem,
 			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))
+			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;
 		}
 

-- 
2.55.0

[PATCH v3 4/4] soc: qcom: smem: ignore multi remote host partitions

[Albert Esteve]

From: Tony Truong <quic_truong@oss.qualcomm.com>

SMEM now supports more than just 1-to-1 partitions. It is possible for
a partition to have multiple remote host and the logic to handle that
does not exist. For now, skip all partitions which has multiple remote
hosts.

Signed-off-by: Tony Truong <quic_truong@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 drivers/soc/qcom/smem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 393257cbe5e1..a7a1840b7ff7 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -89,6 +89,9 @@
 /* Processor/host identifier for the global partition */
 #define SMEM_GLOBAL_HOST	0xfffe
 
+/* Processor/host identifier for multi host partition */
+#define SMEM_MULTI_HOST		0xfffc
+
 /* 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
@@ -1091,6 +1094,9 @@ qcom_smem_enumerate_partitions(struct qcom_smem *smem, u16 local_host)
 		else
 			continue;
 
+		if (remote_host == SMEM_MULTI_HOST)
+			continue;
+
 		if (xa_load(&smem->partitions, remote_host)) {
 			dev_err(smem->dev, "duplicate host %u\n", remote_host);
 			return -EINVAL;

-- 
2.55.0

Re: [PATCH v3 1/4] soc: qcom: smem: add IN_PARTITION_RANGE helper

[Konrad Dybcio]

On 9/24/26 3:10 PM, Albert Esteve wrote:
> From: Sarannya S <quic_sarannya@oss.qualcomm.com>
> 
> Add IN_PARTITION_RANGE() to test that a pointer lies in [start, end]
> and that pointer + size does not wrap.
> 
> Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
> Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
> Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---
>  drivers/soc/qcom/smem.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index b5e7bd8c1512..6783a3c533f0 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) Qualcomm Technologies, Inc. and/or its subsidiaries.
>   */
>  
>  #include <linux/debugfs.h>
> @@ -88,6 +89,17 @@
>  /* 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)))

LLM is unhappy about the 32-bit base and suggests this instead:

#define IN_PARTITION_RANGE(ptr, size, start, end)		\
	((void *)(ptr) >= (void *)(start) &&			\
	 (void *)(ptr) <= (void *)(end) &&			\
	 (size) <= (uintptr_t)(end) - (uintptr_t)(ptr))

Konrad

Re: [PATCH v3 2/4] soc: qcom: smem: validate private entry list walks

[Konrad Dybcio]

On 9/24/26 3:10 PM, Albert Esteve wrote:
> From: Sarannya S <quic_sarannya@oss.qualcomm.com>
> 
> When walking private entries, use the uncached/cached free offsets as
> the list bounds, require room for a header before dereferencing, and
> reject a next pointer that does not advance.
> 
> Skip the cached list when the cached free offset is at the partition
> end.
> 
> Signed-off-by: Sarannya S <quic_sarannya@oss.qualcomm.com>
> Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@oss.qualcomm.com>
> Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@oss.qualcomm.com>
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---

[...]

> -	while (hdr < end) {
> +	while ((hdr + 1) < end) {

This will reject a header that's at the tail of the buffer, need
to make this <= instead

[...]

> -	while (e < end) {
> +	while ((e + 1) < uncached_end) {

Likewise

[...]

> -		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))

And LLM thinks should compare against cached_end

Konrad