From b185e48079fef500e1623a4313d81e8c2ba510c8 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Tue, 9 Mar 2021 19:11:10 +0100 Subject: [PATCH] powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 8873aab8646194a4446117bb617cc71bddda2dee ] All these commands end up peeking into the PACA using the user originated cpu id as an index. Check the cpu id is valid in order to prevent xmon to crash. Instead of printing an error, this follows the same behavior as the "lp s #" command : ignore the buggy cpu id parameter and fall back to the #-less version of the command. Signed-off-by: Greg Kurz Reviewed-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://msgid.link/161531347060.252863.10490063933688958044.stgit@bahia.lan Signed-off-by: Sasha Levin --- arch/powerpc/xmon/xmon.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 8b5277c3b147..4178d5e8b42d 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -1356,7 +1356,7 @@ static int cpu_cmd(void) } termch = cpu; - if (!scanhex(&cpu)) { + if (!scanhex(&cpu) || cpu >= num_possible_cpus()) { /* print cpus waiting or in xmon */ printf("cpus stopped:"); last_cpu = first_cpu = NR_CPUS; @@ -2771,7 +2771,7 @@ static void dump_pacas(void) termch = c; /* Put c back, it wasn't 'a' */ - if (scanhex(&num)) + if (scanhex(&num) && num < num_possible_cpus()) dump_one_paca(num); else dump_one_paca(xmon_owner); @@ -2844,7 +2844,7 @@ static void dump_xives(void) termch = c; /* Put c back, it wasn't 'a' */ - if (scanhex(&num)) + if (scanhex(&num) && num < num_possible_cpus()) dump_one_xive(num); else dump_one_xive(xmon_owner);