From: Gao Xiang <gaoxiang25@huawei.com>
To: Chao Yu <yuchao0@huawei.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
<devel@driverdev.osuosl.org>, <linux-fsdevel@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
<linux-erofs@lists.ozlabs.org>, "Chao Yu" <chao@kernel.org>,
Miao Xie <miaoxie@huawei.com>, <weidu.du@huawei.com>,
Fang Wei <fangwei1@huawei.com>, Gao Xiang <gaoxiang25@huawei.com>
Subject: [PATCH 4/6] staging: erofs: avoid loop in submit chains
Date: Mon, 19 Aug 2019 18:34:24 +0800 [thread overview]
Message-ID: <20190819103426.87579-5-gaoxiang25@huawei.com> (raw)
In-Reply-To: <20190819103426.87579-1-gaoxiang25@huawei.com>
As reported by erofs-utils fuzzer, 2 conditions
can happen in corrupted images, which can cause
unexpected behaviors.
- access the same pcluster one more time;
- access the tail end pcluster again, e.g.
_ access again (will trigger tail merging)
|
1 2 3 1 2 -> 1 2 3 1
|_ tail end of the chain \___/ (unexpected behavior)
Let's detect and avoid them now.
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
drivers/staging/erofs/zdata.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/erofs/zdata.c b/drivers/staging/erofs/zdata.c
index 23283c97fd3b..aae2f2b8353f 100644
--- a/drivers/staging/erofs/zdata.c
+++ b/drivers/staging/erofs/zdata.c
@@ -132,7 +132,7 @@ enum z_erofs_collectmode {
struct z_erofs_collector {
struct z_erofs_pagevec_ctor vector;
- struct z_erofs_pcluster *pcl;
+ struct z_erofs_pcluster *pcl, *tailpcl;
struct z_erofs_collection *cl;
struct page **compressedpages;
z_erofs_next_pcluster_t owned_head;
@@ -353,6 +353,11 @@ static struct z_erofs_collection *cllookup(struct z_erofs_collector *clt,
return NULL;
pcl = container_of(grp, struct z_erofs_pcluster, obj);
+ if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
+ DBG_BUGON(1);
+ erofs_workgroup_put(grp);
+ return ERR_PTR(-EFSCORRUPTED);
+ }
cl = z_erofs_primarycollection(pcl);
if (unlikely(cl->pageofs != (map->m_la & ~PAGE_MASK))) {
@@ -381,6 +386,9 @@ static struct z_erofs_collection *cllookup(struct z_erofs_collector *clt,
}
}
mutex_lock(&cl->lock);
+ /* used to check tail merging loop due to corrupted images */
+ if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
+ clt->tailpcl = pcl;
clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head);
clt->pcl = pcl;
clt->cl = cl;
@@ -434,6 +442,9 @@ static struct z_erofs_collection *clregister(struct z_erofs_collector *clt,
kmem_cache_free(pcluster_cachep, pcl);
return ERR_PTR(-EAGAIN);
}
+ /* used to check tail merging loop due to corrupted images */
+ if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
+ clt->tailpcl = pcl;
clt->owned_head = &pcl->next;
clt->pcl = pcl;
clt->cl = cl;
--
2.17.1
next prev parent reply other threads:[~2019-08-19 10:35 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-17 8:23 [PATCH] erofs: move erofs out of staging Gao Xiang
2019-08-17 21:19 ` Richard Weinberger
2019-08-17 22:07 ` Gao Xiang
2019-08-17 23:25 ` Richard Weinberger
2019-08-17 23:38 ` Gao Xiang
2019-08-18 0:04 ` Gao Xiang
2019-08-18 0:52 ` Gao Xiang
2019-08-18 8:16 ` Richard Weinberger
2019-08-18 8:45 ` Gao Xiang
2019-08-18 9:03 ` Richard Weinberger
2019-08-18 9:09 ` Greg Kroah-Hartman
2019-08-18 9:21 ` Richard Weinberger
2019-08-18 10:12 ` Chao Yu
2019-08-18 15:11 ` Theodore Y. Ts'o
2019-08-18 15:58 ` Christoph Hellwig
2019-08-18 16:16 ` Eric Biggers
2019-08-18 16:22 ` Christoph Hellwig
2019-08-18 16:33 ` Gao Xiang
2019-08-18 17:29 ` Eric Biggers
2019-08-18 17:47 ` Christoph Hellwig
2019-08-18 18:16 ` Gao Xiang
2019-08-18 20:14 ` Gao Xiang
2019-08-19 7:35 ` Richard Weinberger
2019-08-19 8:02 ` Gao Xiang
2019-08-19 10:34 ` [PATCH 0/6] staging: erofs: first stage of corrupted compressed images Gao Xiang
2019-08-19 10:34 ` [PATCH 1/6] staging: erofs: some compressed cluster should be submitted for corrupted images Gao Xiang
2019-08-19 14:36 ` Chao Yu
2019-08-19 14:39 ` Chao Yu
2019-08-19 10:34 ` [PATCH 2/6] staging: erofs: cannot set EROFS_V_Z_INITED_BIT if fill_inode_lazy fails Gao Xiang
2019-08-19 14:43 ` Chao Yu
2019-08-19 10:34 ` [PATCH 3/6] staging: erofs: add two missing erofs_workgroup_put for corrupted images Gao Xiang
2019-08-19 14:40 ` Chao Yu
2019-08-19 10:34 ` Gao Xiang [this message]
2019-08-19 14:50 ` [PATCH 4/6] staging: erofs: avoid loop in submit chains Chao Yu
2019-08-19 10:34 ` [PATCH 5/6] staging: erofs: detect potential multiref due to corrupted images Gao Xiang
2019-08-19 14:57 ` Chao Yu
2019-08-21 2:19 ` Greg Kroah-Hartman
2019-08-21 14:01 ` [PATCH v2 " Gao Xiang
2019-08-21 14:24 ` Chao Yu
2019-08-19 10:34 ` [PATCH 6/6] staging: erofs: avoid endless loop of invalid lookback distance 0 Gao Xiang
2019-08-19 14:58 ` Chao Yu
2019-08-19 16:09 ` [PATCH] erofs: move erofs out of staging Darrick J. Wong
2019-08-19 20:30 ` Gao Xiang
2019-08-20 0:55 ` Qu Wenruo
2019-08-20 1:55 ` Gao Xiang
2019-08-20 2:24 ` Chao Yu
2019-08-20 2:38 ` Qu Wenruo
2019-08-20 7:15 ` Chao Yu
2019-08-20 8:46 ` Qu Wenruo
2019-08-21 2:12 ` Chao Yu
2019-08-20 15:56 ` Theodore Y. Ts'o
2019-08-20 16:35 ` Gao Xiang
2019-08-21 0:51 ` Theodore Y. Ts'o
2019-08-21 1:34 ` Chao Yu
2019-08-21 1:48 ` Darrick J. Wong
2019-08-21 1:57 ` Chao Yu
2019-08-20 3:33 ` Miao Xie
2019-08-20 3:46 ` Gao Xiang
2019-08-20 6:04 ` Qu Wenruo
2019-08-20 6:22 ` Gao Xiang
2019-08-19 7:37 ` Richard Weinberger
2019-08-18 17:43 ` Theodore Y. Ts'o
2019-08-18 16:03 ` Gao Xiang
2019-08-18 17:06 ` Richard Weinberger
2019-08-18 17:46 ` Theodore Y. Ts'o
2019-08-18 18:00 ` Richard Weinberger
2019-08-18 18:31 ` Gao Xiang
2019-08-18 9:28 ` Gao Xiang
2019-08-19 5:28 ` [PATCH] erofs: Use common kernel logging style Joe Perches
2019-08-19 5:52 ` Gao Xiang
2019-08-19 5:47 ` Joe Perches
2019-08-19 6:08 ` Gao Xiang
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