From 7a8bc2b0462eaca0072d1f7f4ddc749fcb8a773c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jan=20H=2E=20Sch=C3=B6nherr?= Date: Fri, 3 Jan 2020 16:07:19 +0100 Subject: [PATCH] x86/mce: Fix use of uninitialized MCE message string MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The function mce_severity() is not required to update its msg argument. In fact, mce_severity_amd() does not, which makes mce_no_way_out() return uninitialized data, which may be used later for printing. Assuming that implementations of mce_severity() either always or never update the msg argument (which is currently the case), it is sufficient to initialize the temporary variable in mce_no_way_out(). While at it, avoid printing a useless "Unknown". Signed-off-by: Jan H. Schönherr Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200103150722.20313-4-jschoenh@amazon.de --- arch/x86/kernel/cpu/mce/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 81b97a6..bfb20c2 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -795,7 +795,7 @@ EXPORT_SYMBOL_GPL(machine_check_poll); static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp, struct pt_regs *regs) { - char *tmp; + char *tmp = *msg; int i; for (i = 0; i < this_cpu_read(mce_num_banks); i++) { @@ -1220,8 +1220,8 @@ void do_machine_check(struct pt_regs *regs, long error_code) DECLARE_BITMAP(toclear, MAX_NR_BANKS); struct mca_config *cfg = &mca_cfg; int cpu = smp_processor_id(); - char *msg = "Unknown"; struct mce m, *final; + char *msg = NULL; int worst = 0; /* -- 2.7.4