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| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-07-11 10:50:47 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-07-29 23:32:26 +0900 |
| commit | de02f2ac5d8cfb311f44f2bf144cc20002f1fbbd (patch) | |
| tree | 44a74007b5eecd2a622d7ace2d3da0612428ea3d /kernel | |
| parent | 02ab7234fc69695736d60b34044fe591689ffadd (diff) | |
| download | lwn-de02f2ac5d8cfb311f44f2bf144cc20002f1fbbd.tar.gz lwn-de02f2ac5d8cfb311f44f2bf144cc20002f1fbbd.zip | |
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')
| -rw-r--r-- | kernel/kprobes.c | 14 |
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; } |