lkml.org 
[lkml]   [2012]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] block: fix ioc leak in put_io_context
Date
When put_io_context is called, if ioc->icq_list is empty and refcount
is 1, kernel will not free the ioc.

This is caught by following kmemleak:

unreferenced object 0xffff880036349fe0 (size 216):
comm "sh", pid 2137, jiffies 4294931140 (age 290579.412s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
01 00 01 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
backtrace:
[<ffffffff8169f926>] kmemleak_alloc+0x26/0x50
[<ffffffff81195a9c>] kmem_cache_alloc_node+0x1cc/0x2a0
[<ffffffff81356b67>] create_io_context_slowpath+0x27/0x130
[<ffffffff81356d2b>] get_task_io_context+0xbb/0xf0
[<ffffffff81055f0e>] copy_process+0x188e/0x18b0
[<ffffffff8105609b>] do_fork+0x11b/0x420
[<ffffffff810247f8>] sys_clone+0x28/0x30
[<ffffffff816d3373>] stub_clone+0x13/0x20
[<ffffffffffffffff>] 0xffffffffffffffff

ioc->release_work() should be used even if ioc->icq_list is empty.

Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
---
block/blk-ioc.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 8b782a6..d74a8ce 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -157,8 +157,7 @@ void put_io_context(struct io_context *ioc)
*/
if (atomic_long_dec_and_test(&ioc->refcount)) {
spin_lock_irqsave(&ioc->lock, flags);
- if (!hlist_empty(&ioc->icq_list))
- schedule_work(&ioc->release_work);
+ schedule_work(&ioc->release_work);
spin_unlock_irqrestore(&ioc->lock, flags);
}
}
--
1.7.5.4


\
 
 \ /
  Last update: 2012-03-12 07:59    [W:1.467 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site