| From 4c975abe3236eb7b7d0a1c24e9b2d6022a3ae319 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 6 May 2019 15:50:18 +0300 |
| Subject: kdb: do a sanity check on the cpu in kdb_per_cpu() |
| |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| |
| [ Upstream commit b586627e10f57ee3aa8f0cfab0d6f7dc4ae63760 ] |
| |
| The "whichcpu" comes from argv[3]. The cpu_online() macro looks up the |
| cpu in a bitmap of online cpus, but if the value is too high then it |
| could read beyond the end of the bitmap and possibly Oops. |
| |
| Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Reviewed-by: Douglas Anderson <dianders@chromium.org> |
| Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| kernel/debug/kdb/kdb_main.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c |
| index 5a58421d7e2d7..a52a6da8c3d09 100644 |
| --- a/kernel/debug/kdb/kdb_main.c |
| +++ b/kernel/debug/kdb/kdb_main.c |
| @@ -2632,7 +2632,7 @@ static int kdb_per_cpu(int argc, const char **argv) |
| diag = kdbgetularg(argv[3], &whichcpu); |
| if (diag) |
| return diag; |
| - if (!cpu_online(whichcpu)) { |
| + if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) { |
| kdb_printf("cpu %ld is not online\n", whichcpu); |
| return KDB_BADCPUNUM; |
| } |
| -- |
| 2.20.1 |
| |
