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authorMasami Hiramatsu (Google) <mhiramat@kernel.org>2023-07-11 10:50:47 +0900
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>2023-07-29 23:32:26 +0900
commitde02f2ac5d8cfb311f44f2bf144cc20002f1fbbd (patch)
tree44a74007b5eecd2a622d7ace2d3da0612428ea3d /kernel/kprobes.c
parent02ab7234fc69695736d60b34044fe591689ffadd (diff)
kprobes: Prohibit probing on CFI preamble symbol
Do not allow to probe on "__cfi_" or "__pfx_" started symbol, because those are used for CFI and not executed. Probing it will break the CFI. Link: https://lore.kernel.org/all/168904024679.116016.18089228029322008512.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 1fc6095d502d..ca385b61d546 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1545,6 +1545,17 @@ static int check_ftrace_location(struct kprobe *p)
return 0;
}
+static bool is_cfi_preamble_symbol(unsigned long addr)
+{
+ char symbuf[KSYM_NAME_LEN];
+
+ if (lookup_symbol_name(addr, symbuf))
+ return false;
+
+ return str_has_prefix("__cfi_", symbuf) ||
+ str_has_prefix("__pfx_", symbuf);
+}
+
static int check_kprobe_address_safe(struct kprobe *p,
struct module **probed_mod)
{
@@ -1563,7 +1574,8 @@ static int check_kprobe_address_safe(struct kprobe *p,
within_kprobe_blacklist((unsigned long) p->addr) ||
jump_label_text_reserved(p->addr, p->addr) ||
static_call_text_reserved(p->addr, p->addr) ||
- find_bug((unsigned long)p->addr)) {
+ find_bug((unsigned long)p->addr) ||
+ is_cfi_preamble_symbol((unsigned long)p->addr)) {
ret = -EINVAL;
goto out;
}