6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kurz <groug@xxxxxxxx> [ 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 <groug@xxxxxxxx> Reviewed-by: Cédric Le Goater <clg@xxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://msgid.link/161531347060.252863.10490063933688958044.stgit@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 d79d6633f3336..bd4813bad317e 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -1350,7 +1350,7 @@ 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; @@ -2772,7 +2772,7 @@ 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); @@ -2845,7 +2845,7 @@ 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); -- 2.43.0