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| author | Corey Minyard <cminyard@mvista.com> | 2019-04-03 15:58:16 -0500 |
|---|---|---|
| committer | Corey Minyard <cminyard@mvista.com> | 2019-04-17 10:29:27 -0500 |
| commit | 3b9a907223d7f6b9d1dadea29436842ae9bcd76d (patch) | |
| tree | 276dafc5c180f29437148e46c22053a156626320 /drivers/char | |
| parent | a885bcfd152f97b25005298ab2d6b741aed9b49c (diff) | |
| download | linux-3b9a907223d7f6b9d1dadea29436842ae9bcd76d.tar.gz linux-3b9a907223d7f6b9d1dadea29436842ae9bcd76d.tar.bz2 linux-3b9a907223d7f6b9d1dadea29436842ae9bcd76d.zip | |
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>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/ipmi/ipmi_msghandler.c | 19 |
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) |