[PATCH] tools/mm/slabinfo: fix buffer overflows in fread operations

[Kaushlendra Kumar <kaushlendra.kumar@intel.com>]

The fread() calls in read_slab_obj() and read_debug_slab_obj() can read
up to sizeof(buffer) bytes, but then unconditionally write a null
terminator at buffer[l]. If fread() returns sizeof(buffer), this writes
beyond the allocated buffer boundaries.

Fix by limiting reads to sizeof(buffer) - 1 bytes in both functions,
ensuring space is always reserved for null termination. This prevents
buffer overflows while maintaining proper string handling.

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
---
 tools/mm/slabinfo.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c
index 1433eff99feb..1a7f2874c625 100644
--- a/tools/mm/slabinfo.c
+++ b/tools/mm/slabinfo.c
@@ -228,7 +228,7 @@ static unsigned long read_slab_obj(struct slabinfo *s, const char *name)
 		buffer[0] = 0;
 		l = 0;
 	} else {
-		l = fread(buffer, 1, sizeof(buffer), f);
+		l = fread(buffer, 1, sizeof(buffer) - 1, f);
 		buffer[l] = 0;
 		fclose(f);
 	}
@@ -247,7 +247,7 @@ static unsigned long read_debug_slab_obj(struct slabinfo *s, const char *name)
 		buffer[0] = 0;
 		l = 0;
 	} else {
-		l = fread(buffer, 1, sizeof(buffer), f);
+		l = fread(buffer, 1, sizeof(buffer) - 1, f);
 		buffer[l] = 0;
 		fclose(f);
 	}
-- 
2.34.1