From 760c6a9139c37e16502362b22656d0cc4e840e8f Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 14 Dec 2016 15:04:14 -0800 Subject: [PATCH] coredump: clarify "unsafe core_pattern" warning 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. Link: http://lkml.kernel.org/r/20161029152124.GA1258@avx2 Signed-off-by: Alexey Dobriyan Acked-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 39b3368f6de6..1475d2545b7e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2389,9 +2389,11 @@ 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 } -- 2.20.1