| Message ID | 1537256432-19807-1-git-send-email-javier@cnexlabs.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lightnvm: pblk: fix race on sysfs line state | expand |
On 09/18/2018 09:40 AM, Javier González wrote: > 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 <javier@cnexlabs.com> > --- > drivers/lightnvm/pblk-core.c | 5 +++-- > drivers/lightnvm/pblk-sysfs.c | 8 +++++++- > 2 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c > index a23e965d32fc..fec0ad68dcd6 100644 > --- a/drivers/lightnvm/pblk-core.c > +++ b/drivers/lightnvm/pblk-core.c > @@ -1662,13 +1662,14 @@ 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; > + > + spin_lock(&l_mg->free_lock); > + cur = l_mg->data_line; > l_mg->data_line = new; > > - spin_lock(&l_mg->free_lock); > 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); > > Applied for 4.20. Thanks.
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index a23e965d32fc..fec0ad68dcd6 100644 --- a/drivers/lightnvm/pblk-core.c +++ b/drivers/lightnvm/pblk-core.c @@ -1662,13 +1662,14 @@ 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; + + spin_lock(&l_mg->free_lock); + cur = l_mg->data_line; l_mg->data_line = new; - spin_lock(&l_mg->free_lock); 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);
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 <javier@cnexlabs.com> --- drivers/lightnvm/pblk-core.c | 5 +++-- drivers/lightnvm/pblk-sysfs.c | 8 +++++++- 2 files changed, 10 insertions(+), 3 deletions(-)