| From 0126026f41dd9fa6ae20dd58974391be32d4c2bd Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 18 Dec 2019 16:44:04 +0800 |
| Subject: block: fix memleak when __blk_rq_map_user_iov() is failed |
| |
| From: Yang Yingliang <yangyingliang@huawei.com> |
| |
| [ Upstream commit 3b7995a98ad76da5597b488fa84aa5a56d43b608 ] |
| |
| When I doing fuzzy test, get the memleak report: |
| |
| BUG: memory leak |
| unreferenced object 0xffff88837af80000 (size 4096): |
| comm "memleak", pid 3557, jiffies 4294817681 (age 112.499s) |
| hex dump (first 32 bytes): |
| 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ |
| 20 00 00 00 10 01 00 00 00 00 00 00 01 00 00 00 ............... |
| backtrace: |
| [<000000001c894df8>] bio_alloc_bioset+0x393/0x590 |
| [<000000008b139a3c>] bio_copy_user_iov+0x300/0xcd0 |
| [<00000000a998bd8c>] blk_rq_map_user_iov+0x2f1/0x5f0 |
| [<000000005ceb7f05>] blk_rq_map_user+0xf2/0x160 |
| [<000000006454da92>] sg_common_write.isra.21+0x1094/0x1870 |
| [<00000000064bb208>] sg_write.part.25+0x5d9/0x950 |
| [<000000004fc670f6>] sg_write+0x5f/0x8c |
| [<00000000b0d05c7b>] __vfs_write+0x7c/0x100 |
| [<000000008e177714>] vfs_write+0x1c3/0x500 |
| [<0000000087d23f34>] ksys_write+0xf9/0x200 |
| [<000000002c8dbc9d>] do_syscall_64+0x9f/0x4f0 |
| [<00000000678d8e9a>] entry_SYSCALL_64_after_hwframe+0x49/0xbe |
| |
| If __blk_rq_map_user_iov() is failed in blk_rq_map_user_iov(), |
| the bio(s) which is allocated before this failing will leak. The |
| refcount of the bio(s) is init to 1 and increased to 2 by calling |
| bio_get(), but __blk_rq_unmap_user() only decrease it to 1, so |
| the bio cannot be freed. Fix it by calling blk_rq_unmap_user(). |
| |
| Reviewed-by: Bob Liu <bob.liu@oracle.com> |
| Reported-by: Hulk Robot <hulkci@huawei.com> |
| Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> |
| Signed-off-by: Jens Axboe <axboe@kernel.dk> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| block/blk-map.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/block/blk-map.c b/block/blk-map.c |
| index 3a62e471d81b..b0790268ed9d 100644 |
| --- a/block/blk-map.c |
| +++ b/block/blk-map.c |
| @@ -151,7 +151,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, |
| return 0; |
| |
| unmap_rq: |
| - __blk_rq_unmap_user(bio); |
| + blk_rq_unmap_user(bio); |
| fail: |
| rq->bio = NULL; |
| return ret; |
| -- |
| 2.20.1 |
| |