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| author | Xiaotian Feng <xtfeng@gmail.com> | 2012-03-14 15:34:48 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-03-14 15:34:48 +0100 |
| commit | ff8c1474cc2f5e11414c71ec4d739c18e6e669c0 (patch) | |
| tree | d498e6e97243a25d20100b9c5a1cee8c73920fb7 | |
| parent | block, sx8: fix pointer math issue getting fw version (diff) | |
| download | linux-ff8c1474cc2f5e11414c71ec4d739c18e6e669c0.tar.xz linux-ff8c1474cc2f5e11414c71ec4d739c18e6e669c0.zip | |
block: fix ioc leak in put_io_context
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>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | 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 92bf55540d87..fb95dd2f889a 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -130,6 +130,7 @@ 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; @@ -144,8 +145,13 @@ 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); |