[PATCH 2/2] ipc: WARN if trying to remove ipc object which is absent

Alexander Mikhalitsyn
2021-07-06T13:40:38Z

Lets produce a warning if we trying to remove non-existing
IPC object from IPC namespace kht/idr structures.

This allows to catch possible bugs when ipc_rmid() function was
called with inconsistent struct ipc_ids*, struct kern_ipc_perm*
arguments.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Milton Miller <miltonm@bga.com>
Cc: Jack Miller <millerjo@us.ibm.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
---
ipc/util.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/ipc/util.c b/ipc/util.c
index 0027e47626b7..45bb8ce6c42c 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -447,8 +447,8 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
if (ipcp->key != IPC_PRIVATE)
- rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
- ipc_kht_params);
+ WARN_ON(rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
+ ipc_kht_params));
}

/**
@@ -498,7 +498,7 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
int idx = ipcid_to_idx(ipcp->id);

- idr_remove(&ids->ipcs_idr, idx);
+ WARN_ON(idr_remove(&ids->ipcs_idr, idx) != ipcp);
ipc_kht_remove(ids, ipcp);
ids->in_use--;
ipcp->deleted = true;
--
2.31.1