[PATCH] ipc/msg: avoid negative value by overflow in msginfo

Jiebin Sun
2022-09-20T06:49:00Z

The 32-bit value in msginfo struct could be negative if we get it
from signed 64-bit. Clamping it to INT_MAX helps to avoid the
negative value by overflow.

Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
Reviewed-by: Manfred Spraul <manfred@colorfullif.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
---
ipc/msg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ipc/msg.c b/ipc/msg.c
index f2bb4c193ecf..65f437e28c9b 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -501,8 +501,8 @@ static int msgctl_info(struct ipc_namespace *ns, int msqid,
max_idx = ipc_get_maxidx(&msg_ids(ns));
up_read(&msg_ids(ns).rwsem);
if (cmd == MSG_INFO) {
- msginfo->msgmap = percpu_counter_sum(&ns->percpu_msg_hdrs);
- msginfo->msgtql = percpu_counter_sum(&ns->percpu_msg_bytes);
+ msginfo->msgmap = min(percpu_counter_sum(&ns->percpu_msg_hdrs), INT_MAX);
+ msginfo->msgtql = min(percpu_counter_sum(&ns->percpu_msg_bytes), INT_MAX);
} else {
msginfo->msgmap = MSGMAP;
msginfo->msgpool = MSGPOOL;
--
2.31.1