This is a note to let you know that I've just added the patch titled
powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#"
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-xmon-check-cpu-id-in-commands-c-dp-and-dx.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 100e11cafb6fa96d33370020d88605c2fa02fc76
Author: Greg Kurz <groug@xxxxxxxx>
Date: Tue Mar 9 19:11:10 2021 +0100
powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#"
[ 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>
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 3291e5fb94bcc..cd6df90dc6720 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1154,7 +1154,7 @@ static int cpu_cmd(void)
unsigned long cpu, first_cpu, last_cpu;
int timeout;
- 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;
@@ -2485,7 +2485,7 @@ 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);
@@ -2568,7 +2568,7 @@ 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);
