From 64b4c411a6c7a5f27555bfc2d6310b87bde3db67 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Thu, 20 Oct 2022 21:19:22 -0700
Subject: [PATCH] ipc/msg.c: fix percpu_counter use after free
These percpu counters are referenced in free_ipcs->freeque, so destroy
them later.
Fixes: 72d1e611082e ("ipc/msg: mitigate the lock contention with percpu counter")
Reported-by: syzbot+96e659d35b9d6b541152@syzkaller.appspotmail.com
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jiebin Sun <jiebin.sun@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
ipc/msg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/ipc/msg.c b/ipc/msg.c
index e4e0990e08f75..fd08b3cb36d79 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -1329,11 +1329,11 @@ fail_msg_bytes:
#ifdef CONFIG_IPC_NS
void msg_exit_ns(struct ipc_namespace *ns)
{
- percpu_counter_destroy(&ns->percpu_msg_bytes);
- percpu_counter_destroy(&ns->percpu_msg_hdrs);
free_ipcs(ns, &msg_ids(ns), freeque);
idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht);
+ percpu_counter_destroy(&ns->percpu_msg_bytes);
+ percpu_counter_destroy(&ns->percpu_msg_hdrs);
}
#endif
--
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