When kexec_iomem_for_each_line() reads from /proc/iomem,
concurrent modifications to /proc/iomem may lead to
usablemem_rgns recording duplicate Crash kernel segments.
This can result in the number of retrieved Crash kernel
segments exceeding CRASH_MAX_RESERVED_RANGES, triggering
a realloc of the crash_reserved_mem in usablemem_rgns,
which could crash the process. We should ensure that each
range added to usablemem_rgns is unique to prevent these issues.
Reviewed-by: Louhongxiang <louhongxiang@xxxxxxxxxx>
Reviewed-by: wangbin <wangbin224@xxxxxxxxxx>
Reviewed-by: yangyanchao <yangyanchao6@xxxxxxxxxx>
Signed-off-by: chenhaixiang <chenhaixiang3@xxxxxxxxxx>
---
kexec/arch/arm64/crashdump-arm64.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c
index 3098315..f23b2bf 100644
--- a/kexec/arch/arm64/crashdump-arm64.c
+++ b/kexec/arch/arm64/crashdump-arm64.c
@@ -63,10 +63,22 @@ static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr),
char *str, unsigned long long base,
unsigned long long length)
{
- if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0)
+ int i;
+
+ if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0) {
+ /*
+ * Checks whether the area exists in crash_reserved_mem.
+ */
+ for (i = 0; i < usablemem_rgns.max_size; i++) {
+ if (usablemem_rgns.ranges[i].start == base) {
+ fprintf(stderr, "Warning, the range already exists in usablemem_rgns, base=%lx, length=%lx\n",
+ base, length);
+ return 0;
+ }
+ }
return mem_regions_alloc_and_add(&usablemem_rgns,
base, length, RANGE_RAM);
- else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0)
+ } else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0)
return mem_regions_alloc_and_add(&system_memory_rgns,
base, length, RANGE_RAM);
else if (strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) == 0) {
--
2.41.0
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