[PATCH] cachefiles: Fix a sleep-in-atomic bug in cachefiles_printk_object

From	Jia-Ju Bai <baijiaju1990@163.com>
Newsgroups	linux.kernel
Subject	[PATCH] cachefiles: Fix a sleep-in-atomic bug in cachefiles_printk_object
Date	2017-06-05 06:10 +0200
Message-ID	<tORv3-6jd-1@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

The driver may sleep under a write spin lock, and the function 
call path is:
cachefiles_mark_object_active (acquire the lock by write_lock)
  cachefiles_printk_object
    kmalloc(GFP_NOIO) --> may sleep
cachefiles_mark_object_buried (acquire the lock by write_lock)
  cachefiles_printk_object
    kmalloc(GFP_NOIO) --> may sleep

To fix it, "GFP_NOIO" is replaced with "GFP_ATOMIC".

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
 fs/cachefiles/namei.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 41df8a2..d0f76e7 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -83,7 +83,7 @@ static noinline void cachefiles_printk_object(struct cachefiles_object *object,
 {
 	u8 *keybuf;
 
-	keybuf = kmalloc(CACHEFILES_KEYBUF_SIZE, GFP_NOIO);
+	keybuf = kmalloc(CACHEFILES_KEYBUF_SIZE, GFP_ATOMIC);
 	if (object)
 		__cachefiles_printk_object(object, "", keybuf);
 	if (xobject)
-- 
1.7.9.5

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH] cachefiles: Fix a sleep-in-atomic bug in cachefiles_printk_object Jia-Ju Bai <baijiaju1990@163.com> - 2017-06-05 06:10 +0200

csiph-web