From: Javier González Date: Tue, 9 Oct 2018 11:12:07 +0000 (+0200) Subject: lightnvm: pblk: fix race on sysfs line state X-Git-Tag: Ubuntu-5.13.0-19.19~9993^2~57 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=44cdbdc657b23f75736eca3e88b781f009104363;p=mirror_ubuntu-jammy-kernel.git lightnvm: pblk: fix race on sysfs line state pblk exposes a sysfs interface that represents its internal state. Part of this state is the map bitmap for the current open line, which should be protected by the line lock to avoid a race when freeing the line metadata. Currently, it is not. This patch makes sure that the line state is consistent and NULL bitmap pointers are not dereferenced. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index 4045a9b1ee74..6944aac43b01 100644 --- a/drivers/lightnvm/pblk-core.c +++ b/drivers/lightnvm/pblk-core.c @@ -1611,13 +1611,14 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk) struct pblk_line *cur, *new = NULL; unsigned int left_seblks; - cur = l_mg->data_line; new = l_mg->data_next; if (!new) goto out; - l_mg->data_line = new; spin_lock(&l_mg->free_lock); + cur = l_mg->data_line; + l_mg->data_line = new; + pblk_line_setup_metadata(new, l_mg, &pblk->lm); spin_unlock(&l_mg->free_lock); diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c index cba83ac43e62..2d2818155aa8 100644 --- a/drivers/lightnvm/pblk-sysfs.c +++ b/drivers/lightnvm/pblk-sysfs.c @@ -263,8 +263,14 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page) sec_in_line = l_mg->data_line->sec_in_line; meta_weight = bitmap_weight(&l_mg->meta_bitmap, PBLK_DATA_LINES); - map_weight = bitmap_weight(l_mg->data_line->map_bitmap, + + spin_lock(&l_mg->data_line->lock); + if (l_mg->data_line->map_bitmap) + map_weight = bitmap_weight(l_mg->data_line->map_bitmap, lm->sec_per_line); + else + map_weight = 0; + spin_unlock(&l_mg->data_line->lock); } spin_unlock(&l_mg->free_lock);