From cc5bd925f194c8dc7e2a4eee2c81a4f148018b08 Mon Sep 17 00:00:00 2001 From: "tang.junhui" Date: Fri, 4 Nov 2016 12:37:09 +0800 Subject: [PATCH] dm mpath: add checks for priority group count to avoid invalid memory access This avoids the potential for invalid memory access, if/when there are no priority groups, in response to invalid arguments being sent by the user via DM message (e.g. "switch_group", "disable_group" or "enable_group"). Signed-off-by: tang.junhui Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index d234b6c33646..f8369697af12 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1364,7 +1364,7 @@ static int switch_pg_num(struct multipath *m, const char *pgstr) char dummy; if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || - (pgnum > m->nr_priority_groups)) { + !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { DMWARN("invalid PG number supplied to switch_pg_num"); return -EINVAL; } @@ -1396,7 +1396,7 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) char dummy; if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || - (pgnum > m->nr_priority_groups)) { + !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { DMWARN("invalid PG number supplied to bypass_pg"); return -EINVAL; } -- 2.39.5