Messages in this thread Patch in this message | | | From | Xiaotian Feng <> | Subject | [PATCH v2] block: fix ioc leak in put_io_context | Date | Tue, 13 Mar 2012 13:21:06 -0400 |
| |
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 should be freed if ioc->icq_list is empty. Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com> --- block/blk-ioc.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 8b782a6..9690f27 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -145,6 +145,7 @@ static void ioc_release_fn(struct work_struct *work) void put_io_context(struct io_context *ioc) { unsigned long flags; + bool free_ioc = false; if (ioc == NULL) return; @@ -159,8 +160,13 @@ void put_io_context(struct io_context *ioc) spin_lock_irqsave(&ioc->lock, flags); if (!hlist_empty(&ioc->icq_list)) schedule_work(&ioc->release_work); + else + free_ioc = true; spin_unlock_irqrestore(&ioc->lock, flags); } + + if (free_ioc) + kmem_cache_free(iocontext_cachep, ioc); } EXPORT_SYMBOL(put_io_context); -- 1.7.5.4
| |