From: Zhong Jinghua <zhongjinghua@huawei.com> stable inclusion from stable-v4.19.312 commit 832580af82ace363205039a8e7c4ef04552ccc1a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IC2E65 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ------------------ [ 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.... Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: drivers/block/loop.c [Context conflicts.] Signed-off-by: Zheng Qixing <zhengqixing@huawei.com> --- drivers/block/loop.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index d1d6aeaa81a7..026cde240c4a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1283,13 +1283,17 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) lo->lo_device->bd_inode->i_mapping->nrpages); goto out_unfreeze; } + + /* Avoid assigning overflow values */ + if (info->lo_offset > LLONG_MAX || info->lo_sizelimit > LLONG_MAX) { + err = -EOVERFLOW; + goto out_unfreeze; + } + if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) { err = -EFBIG; goto out_unfreeze; } - /* loff_t vars have been assigned __u64 */ - if (lo->lo_offset < 0 || lo->lo_sizelimit < 0) - return -EOVERFLOW; } loop_config_discard(lo); -- 2.39.2