From b8d0220d588a204ed4bcb56cec45d3cbe9f66d0e Mon Sep 17 00:00:00 2001 From: Zhong Jinghua Date: Fri, 14 Jul 2023 16:07:52 +0800 Subject: [PATCH] loop: loop_set_status_from_info() check before assignment stable inclusion from stable-v5.10.173 commit c79a924ed6afac1708dfd370ba66bcf6a852ced6 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7JHOA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c79a924ed6afac1708dfd370ba66bcf6a852ced6 -------------------------------- [ 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 Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Zhong Jinghua (cherry picked from commit cfb3aa6f4830bdbf1edd9f7517d58ff2379ed752) --- 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 60f2a31c4a24..0bb2e46cefab 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1029,13 +1029,13 @@ 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; -- Gitee