public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH] coredump: clarify "unsafe core_pattern" warning
@ 2016-10-29 15:21 Alexey Dobriyan
  2016-10-29 16:00 ` Kees Cook
  0 siblings, 1 reply; 2+ messages in thread
From: Alexey Dobriyan @ 2016-10-29 15:21 UTC (permalink / raw)
  To: akpm; +Cc: linux-kernel, keescook

I was amused to find "unsafe core_pattern" warning having these lines
in /etc/sysctl.conf:

	fs.suid_dumpable=2
	kernel.core_pattern=/core/core-%e-%p-%E
	kernel.core_uses_pid=0

Turns out kernel is formally right. Default core_pattern is just "core",
which doesn't qualify for secure path while setting suid.dumpable.

Hint admins about solution, clarify sysctl names, delete unnecessary '\'
characters (string literals are concatenated regardless) and reformat
for easier grepping.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 kernel/sysctl.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

commit ba93b14a4f61e4563134abab5d81bb8b53c60df9
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date:   Sat Oct 29 18:13:57 2016 +0300

    kernel.core_dump

--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2403,9 +2403,11 @@ static void validate_coredump_safety(void)
 #ifdef CONFIG_COREDUMP
 	if (suid_dumpable == SUID_DUMP_ROOT &&
 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
-		printk(KERN_WARNING "Unsafe core_pattern used with "\
-			"suid_dumpable=2. Pipe handler or fully qualified "\
-			"core dump path required.\n");
+		printk(KERN_WARNING
+"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
+"Pipe handler or fully qualified core dump path required.\n"
+"Set kernel.core_pattern before fs.suid_dumpable.\n"
+		);
 	}
 #endif
 }

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2016-10-29 16:00 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-10-29 15:21 [PATCH] coredump: clarify "unsafe core_pattern" warning Alexey Dobriyan
2016-10-29 16:00 ` Kees Cook

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox