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authorCorey Minyard <cminyard@mvista.com>2019-04-03 15:58:16 -0500
committerCorey Minyard <cminyard@mvista.com>2019-04-17 10:29:27 -0500
commit3b9a907223d7f6b9d1dadea29436842ae9bcd76d (patch)
tree276dafc5c180f29437148e46c22053a156626320
parenta885bcfd152f97b25005298ab2d6b741aed9b49c (diff)
ipmi: fix sleep-in-atomic in free_user at cleanup SRCU user->release_barrier
free_user() could be called in atomic context. This patch pushed the free operation off into a workqueue. Example: BUG: sleeping function called from invalid context at kernel/workqueue.c:2856 in_atomic(): 1, irqs_disabled(): 0, pid: 177, name: ksoftirqd/27 CPU: 27 PID: 177 Comm: ksoftirqd/27 Not tainted 4.19.25-3 #1 Hardware name: AIC 1S-HV26-08/MB-DPSB04-06, BIOS IVYBV060 10/21/2015 Call Trace: dump_stack+0x5c/0x7b ___might_sleep+0xec/0x110 __flush_work+0x48/0x1f0 ? try_to_del_timer_sync+0x4d/0x80 _cleanup_srcu_struct+0x104/0x140 free_user+0x18/0x30 [ipmi_msghandler] ipmi_free_recv_msg+0x3a/0x50 [ipmi_msghandler] deliver_response+0xbd/0xd0 [ipmi_msghandler] deliver_local_response+0xe/0x30 [ipmi_msghandler] handle_one_recv_msg+0x163/0xc80 [ipmi_msghandler] ? dequeue_entity+0xa0/0x960 handle_new_recv_msgs+0x15c/0x1f0 [ipmi_msghandler] tasklet_action_common.isra.22+0x103/0x120 __do_softirq+0xf8/0x2d7 run_ksoftirqd+0x26/0x50 smpboot_thread_fn+0x11d/0x1e0 kthread+0x103/0x140 ? sort_range+0x20/0x20 ? kthread_destroy_worker+0x40/0x40 ret_from_fork+0x1f/0x40 Fixes: 77f8269606bf ("ipmi: fix use-after-free of user->release_barrier.rda") Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Corey Minyard <cminyard@mvista.com> Cc: stable@vger.kernel.org # 5.0 Cc: Yang Yingliang <yangyingliang@huawei.com>
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index e8ba67834746..00bf4b17edbf 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -214,6 +214,9 @@ struct ipmi_user {
/* Does this interface receive IPMI events? */
bool gets_events;
+
+ /* Free must run in process context for RCU cleanup. */
+ struct work_struct remove_work;
};
static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user, int *index)
@@ -1157,6 +1160,15 @@ static int intf_err_seq(struct ipmi_smi *intf,
return rv;
}
+static void free_user_work(struct work_struct *work)
+{
+ struct ipmi_user *user = container_of(work, struct ipmi_user,
+ remove_work);
+
+ cleanup_srcu_struct(&user->release_barrier);
+ kfree(user);
+}
+
int ipmi_create_user(unsigned int if_num,
const struct ipmi_user_hndl *handler,
void *handler_data,
@@ -1200,6 +1212,8 @@ int ipmi_create_user(unsigned int if_num,
goto out_kfree;
found:
+ INIT_WORK(&new_user->remove_work, free_user_work);
+
rv = init_srcu_struct(&new_user->release_barrier);
if (rv)
goto out_kfree;
@@ -1260,8 +1274,9 @@ EXPORT_SYMBOL(ipmi_get_smi_info);
static void free_user(struct kref *ref)
{
struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
- cleanup_srcu_struct(&user->release_barrier);
- kfree(user);
+
+ /* SRCU cleanup must happen in task context. */
+ schedule_work(&user->remove_work);
}
static void _ipmi_destroy_user(struct ipmi_user *user)