From: Damien Le Moal <dlemoal@kernel.org> mainline inclusion from mainline-v6.10-rc2 commit d9ff882b54f99f96787fa3df7cd938966843c418 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA7D6H CVE: CVE-2024-36478 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- When powering on a null_blk device that is not already on, the return value ret that is initialized to be count is reused to check the return value of null_add_dev(), leading to nullb_device_power_store() to return null_add_dev() return value (0 on success) instead of "count". So make sure to set ret to be equal to count when there are no errors. Fixes: a2db328b0839 ("null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'") Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20240527043445.235267-1-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Li Nan <linan122@huawei.com> --- drivers/block/null_blk/main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index b339bb6239c3..c70c1b9caf2f 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -470,6 +470,7 @@ static ssize_t nullb_device_power_store(struct config_item *item, set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); dev->power = newp; + ret = count; } else if (dev->power && !newp) { if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { dev->power = newp; -- 2.39.2