lkml.org 
[lkml]   [2019]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] crypto: pcrypt: Fix possible deadlock in padata_sysfs_release
Date
There is a deadlock issue in pcrypt_init_padata(),

pcrypt_init_padata()
cpus_read_lock()
padata_free()
padata_sysfs_release()
cpus_read_lock()

Narrow rcu_read_lock/unlock() and move put_online_cpus()
before padata_free() to fix it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
crypto/pcrypt.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 0e9ce329fd47..f3dacb714cd4 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -407,16 +407,19 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
int ret = -ENOMEM;
struct pcrypt_cpumask *mask;

- get_online_cpus();

pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
1, name);
if (!pcrypt->wq)
goto err;

+ get_online_cpus();
+
pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
- if (!pcrypt->pinst)
+ if (!pcrypt->pinst) {
+ put_online_cpus();
goto err_destroy_workqueue;
+ }

mask = kmalloc(sizeof(*mask), GFP_KERNEL);
if (!mask)
@@ -448,12 +451,11 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
free_cpumask_var(mask->mask);
kfree(mask);
err_free_padata:
+ put_online_cpus();
padata_free(pcrypt->pinst);
err_destroy_workqueue:
destroy_workqueue(pcrypt->wq);
err:
- put_online_cpus();
-
return ret;
}

--
2.20.1
\
 
 \ /
  Last update: 2019-06-01 11:16    [W:0.046 / U:3.004 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site