From bc4f2f5469ac2a52affadc4c00c1276d76151a39 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 Apr 2018 16:32:33 -0700 Subject: [PATCH] taint: add taint for randstruct Since the randstruct plugin can intentionally produce extremely unusual kernel structure layouts (even performance pathological ones), some maintainers want to be able to trivially determine if an Oops is coming from a randstruct-built kernel, so as to keep their sanity when debugging. This adds the new flag and initializes taint_mask immediately when built with randstruct. Link: http://lkml.kernel.org/r/1519084390-43867-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Reviewed-by: Andrew Morton Cc: Al Viro Cc: Alexey Dobriyan Cc: Jonathan Corbet Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/kernel.txt | 1 + include/linux/kernel.h | 3 ++- kernel/panic.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 4a890c7fb6c3..eded671d55eb 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -991,6 +991,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports. 16384 (L): A soft lockup has previously occurred on the system. 32768 (K): The kernel has been live patched. 65536 (X): Auxiliary taint, defined and used by for distros. +131072 (T): The kernel was built with the struct randomization plugin. ============================================================== diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 086e8e80f765..6a1eb0b0aad9 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -562,7 +562,8 @@ extern enum system_states { #define TAINT_SOFTLOCKUP 14 #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 -#define TAINT_FLAGS_COUNT 17 +#define TAINT_RANDSTRUCT 17 +#define TAINT_FLAGS_COUNT 18 struct taint_flag { char c_true; /* character printed when tainted */ diff --git a/kernel/panic.c b/kernel/panic.c index 5ceb9cbec4a2..42e487488554 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -34,7 +34,8 @@ #define PANIC_BLINK_SPD 18 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; -static unsigned long tainted_mask; +static unsigned long tainted_mask = + IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; static int pause_on_oops; static int pause_on_oops_flag; static DEFINE_SPINLOCK(pause_on_oops_lock); @@ -325,6 +326,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, + [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, }; /** -- 2.39.5