[PATCH 1/2] soc: qcom: smem: add boundary checks for partitions
From: Albert Esteve
Date: Thu Aug 20 2026 - 07:34:57 EST
From: Sudeepgoud Patil <quic_sudeepgo@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@xxxxxxxxxxx>
Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@xxxxxxxxxxx>
Signed-off-by: Albert Esteve <aesteve@xxxxxxxxxx>
---
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