From: Genjian <zhanggenjian@126.com>
To: stable@vger.kernel.org
Cc: axboe@kernel.dk, stable@kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, zhanggenjian123@gmail.com,
Zhong Jinghua <zhongjinghua@huawei.com>,
Chaitanya Kulkarni <kch@nvidia.com>,
Genjian Zhang <zhanggenjian@kylinos.cn>
Subject: [PATCH linux-5.4.y 8/8] loop: loop_set_status_from_info() check before assignment
Date: Thu, 7 Mar 2024 12:14:11 +0800 [thread overview]
Message-ID: <20240307041411.3792061-9-zhanggenjian@126.com> (raw)
In-Reply-To: <20240307041411.3792061-1-zhanggenjian@126.com>
From: Zhong Jinghua <zhongjinghua@huawei.com>
[ Upstream commit 9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa ]
In loop_set_status_from_info(), lo->lo_offset and lo->lo_sizelimit should
be checked before reassignment, because if an overflow error occurs, the
original correct value will be changed to the wrong value, and it will not
be changed back.
More, the original patch did not solve the problem, the value was set and
ioctl returned an error, but the subsequent io used the value in the loop
driver, which still caused an alarm:
loop_handle_cmd
do_req_filebacked
loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
lo_rw_aio
cmd->iocb.ki_pos = pos
Fixes: c490a0b5a4f3 ("loop: Check for overflow while configuring loop")
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn>
---
drivers/block/loop.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c999eef4e345..ff452c02b61f 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1296,13 +1296,13 @@ loop_set_status_from_info(struct loop_device *lo,
if (err)
return err;
+ /* Avoid assigning overflow values */
+ if (info->lo_offset > LLONG_MAX || info->lo_sizelimit > LLONG_MAX)
+ return -EOVERFLOW;
+
lo->lo_offset = info->lo_offset;
lo->lo_sizelimit = info->lo_sizelimit;
- /* loff_t vars have been assigned __u64 */
- if (lo->lo_offset < 0 || lo->lo_sizelimit < 0)
- return -EOVERFLOW;
-
memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
lo->lo_file_name[LO_NAME_SIZE-1] = 0;
--
2.25.1
prev parent reply other threads:[~2024-03-07 4:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-07 4:14 [PATCH linux-5.4.y 0/8] Fix the UAF issue caused by the loop driver Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 1/8] Revert "loop: Check for overflow while configuring loop" Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 2/8] loop: Call loop_config_discard() only after new config is applied Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 3/8] loop: Remove sector_t truncation checks Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 4/8] loop: Factor out setting loop device size Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 5/8] loop: Refactor loop_set_status() size calculation Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 6/8] loop: Factor out configuring loop from status Genjian
2024-03-07 4:14 ` [PATCH linux-5.4.y 7/8] loop: Check for overflow while configuring loop Genjian
2024-03-07 4:14 ` Genjian [this message]
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