On 29/07/26 06:59, Jinjie Ruan wrote:
A static Sashiko AI review identified a potential NULL pointer
dereference in kexec_extra_fdt_size_ppc64().
On platforms without any reserved memory regions,
get_reserved_memory_ranges() can return 0 while leaving 'rmem'
unallocated as NULL. Passing it directly leads to a kernel panic when
evaluating 'rmem->nr_ranges'.
Yes that is possible, so it is worth adding NULL check for rmem.
Feel free to add:
Reviewed-by: Sourabh Jain <[email protected]>
Add a NULL check for 'rmem' to prevent this crash.
Cc: Sourabh Jain <[email protected]>
Cc: Hari Bathini <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: [email protected]
Fixes: 0d3ff067331e ("powerpc/kexec_file: fix extra size calculation for kexec
FDT")
Signed-off-by: Jinjie Ruan <[email protected]>
---
arch/powerpc/kexec/file_load_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kexec/file_load_64.c
b/arch/powerpc/kexec/file_load_64.c
index 8c72e12ea44e..6075b1c88511 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -664,7 +664,7 @@ unsigned int kexec_extra_fdt_size_ppc64(struct kimage
*image, struct crash_mem *
extra_size += (cpu_nodes - boot_cpu_node_count) *
cpu_node_size();
/* Consider extra space for reserved memory ranges if any */
- if (rmem->nr_ranges > 0)
+ if (rmem && rmem->nr_ranges > 0)
extra_size += sizeof(struct fdt_reserve_entry) *
rmem->nr_ranges;
return extra_size + kdump_extra_fdt_size_ppc64(image, cpu_nodes);
