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ACPI/IORT: Fix memory leak in iort_rmr_alloc_sids()

PATCH Applied Miaoqian Lin 4 participants 4 messages Aug 28, 2025 – Sep 5, 2025

Subsystems (4)
Stable branch ACPI BPF ACPI arm64
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Miaoqian Lin

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#0 lore raw

PATCH 1/1 ACPI/IORT: Fix memory leak in iort_rmr_alloc_sids()

If krealloc_array() fails in iort_rmr_alloc_sids(), the function returns NULL but does not free the original 'sids' allocation. This results in a memory leak since the caller overwrites the original pointer with the NULL return value.

Fixes 491cf4a6735a ("ACPI/IORT: Add support to retrieve IORT RMR reserved regions")
Cc <[email protected]>
Signed-off-by Miaoqian Lin <[email protected]>

---
This follows the same pattern as the fix in commit 06615967d488 ("bpf, verifier: Fix memory leak in array reallocation for stack state").

---
 drivers/acpi/arm64/iort.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/acpi/arm64/iort.c +3 -1
index 98759d6199d3..65f0f56ad753 100644
@@ -937,8 +937,10 @@ static u32 *iort_rmr_alloc_sids(u32 *sids, u32 count, u32 id_start,
 
 	new_sids = krealloc_array(sids, count + new_count,
 				  sizeof(*new_sids), GFP_KERNEL);
-	if (!new_sids)
+	if (!new_sids) {
+		kfree(sids);
 		return NULL;
+	}
 
 	for (i = count; i < total_count; i++)
 		new_sids[i] = id_start++;
Signature · 1 line
2.39.5 (Apple Git-154)
maintainer Reviewed-by on v1 1/1
#1 lore raw

+Cc Catalin, Will

Quoted 21 lines · Miaoqian Lin

If krealloc_array() fails in iort_rmr_alloc_sids(), the function returns NULL but does not free the original 'sids' allocation. This results in a memory leak since the caller overwrites the original pointer with the NULL return value.

Fixes 491cf4a6735a ("ACPI/IORT: Add support to retrieve IORT RMR reserved regions")
Cc <[email protected]>
Signed-off-by Miaoqian Lin <[email protected]>

---
This follows the same pattern as the fix in commit 06615967d488 ("bpf, verifier: Fix memory leak in array reallocation for stack state").

---
  drivers/acpi/arm64/iort.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)
drivers/acpi/arm64/iort.c +0 -0
index 98759d6199d3..65f0f56ad753 100644
@@ -937,8 +937,10 @@ static u32 *iort_rmr_alloc_sids(u32 *sids, u32 count, u32 id_start,

drivers/acpi/arm64/iort.c static u32 *iort_rmr_alloc_sids(u32 *sids, u32 count, u32 id_start, · line 946

Quoted 10 lines
drivers/acpi/arm64/iort.c +3 -1
  	new_sids = krealloc_array(sids, count + new_count,
  				  sizeof(*new_sids), GFP_KERNEL);
-	if (!new_sids)
+	if (!new_sids) {
+		kfree(sids);
  		return NULL;
+	}
 
  	for (i = count; i < total_count; i++)
  		new_sids[i] = id_start++;

Good catch!

Reviewed-by Hanjun Guo <[email protected]>

Thanks
Hanjun

#2 lore raw
In reply to Miaoqian Lin
Quoted 2 lines

If krealloc_array() fails in iort_rmr_alloc_sids(), the function returns NULL but does not free the original 'sids' allocation. …

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.17-rc4#n94

…

Quoted 3 lines

---
This follows the same pattern as the fix in commit 06615967d488 ("bpf, verifier: Fix memory leak in array reallocation for stack state").

…

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.17-rc4&id=42378a9ca55347102bbf86708776061d8fe3ece2

Regards,
Markus

maintainer Applied
#3 lore raw
In reply to Miaoqian Lin
Quoted 6 lines · Miaoqian Lin

If krealloc_array() fails in iort_rmr_alloc_sids(), the function returns NULL but does not free the original 'sids' allocation. This results in a memory leak since the caller overwrites the original pointer with the NULL return value.

Applied to arm64 (for-next/fixes), thanks!

[1/1] ACPI/IORT: Fix memory leak in iort_rmr_alloc_sids()

      https://git.kernel.org/arm64/c/f3ef7110924b
Signature · 1 line
Catalin