[PATCH] kallsyms: don't leak address when printing symbol

From: Tobin C. Harding
Date: Wed Nov 08 2017 - 20:50:59 EST


Currently if a pointer is printed using %p[ssB] and the symbol is not
found (kallsyms_lookup() fails) then we print the actual address. This
leaks kernel addresses. We should instead print something _safe_.

Print "<no-symbol>" instead of kernel address.

Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
---
kernel/kallsyms.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 127e7cfafa55..182e7592be9c 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -390,7 +390,7 @@ static int __sprint_symbol(char *buffer, unsigned long address,
address += symbol_offset;
name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
if (!name)
- return sprintf(buffer, "0x%lx", address - symbol_offset);
+ return sprintf(buffer, "<no-symbol>");

if (name != buffer)
strcpy(buffer, name);
--
2.7.4