kprobes: Do not expose probe addresses to non-CAP_SYSLOG

The kprobe show() functions were using "current"'s creds instead
of the file opener's creds for kallsyms visibility. Fix to use
seq_file->file->f_cred.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 81365a947d ("kprobes: Show address of kprobes if kallsyms does")
Fixes: ffb9bd68eb ("kprobes: Show blacklist addresses as same as kallsyms does")
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2020-07-02 15:20:22 -07:00
parent b25a7c5af9
commit 60f7bb66b8

View File

@ -2448,7 +2448,7 @@ static void report_probe(struct seq_file *pi, struct kprobe *p,
else
kprobe_type = "k";
if (!kallsyms_show_value(current_cred()))
if (!kallsyms_show_value(pi->file->f_cred))
addr = NULL;
if (sym)
@ -2540,7 +2540,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
* If /proc/kallsyms is not showing kernel address, we won't
* show them here either.
*/
if (!kallsyms_show_value(current_cred()))
if (!kallsyms_show_value(m->file->f_cred))
seq_printf(m, "0x%px-0x%px\t%ps\n", NULL, NULL,
(void *)ent->start_addr);
else