When we are using PBLK with 0 sized metadata during recovery
process we need to reference a last page of bio. Currently
KASAN reports use-after-free in that case, since bio is
freed on IO completion.
This patch adds addtional bio reference to ensure, that we
can still use bio memory after IO completion. It also ensures
that we are not reusing the same bio on retry_rq path.
Reported-by: Hans Holmberg <hans.holmberg@xxxxxxxxxxxx>
Signed-off-by: Igor Konopko <igor.j.konopko@xxxxxxxxx>
---
drivers/lightnvm/pblk-recovery.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 009faf5db40f..3fcf062d752c 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -376,12 +376,14 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
rq_ppas = pblk->min_write_pgs;
rq_len = rq_ppas * geo->csecs;
+retry_rq:
bio = bio_map_kern(dev->q, data, rq_len, GFP_KERNEL);
if (IS_ERR(bio))
return PTR_ERR(bio);
bio->bi_iter.bi_sector = 0; /* internal bio */
bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ bio_get(bio);
rqd->bio = bio;
rqd->opcode = NVM_OP_PREAD;
@@ -394,7 +396,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
if (pblk_io_aligned(pblk, rq_ppas))
rqd->is_seq = 1;
-retry_rq:
for (i = 0; i < rqd->nr_ppas; ) {
struct ppa_addr ppa;
int pos;
@@ -417,6 +418,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
if (ret) {
pblk_err(pblk, "I/O submission failed: %d\n", ret);
bio_put(bio);
+ bio_put(bio);
return ret;
}
@@ -428,19 +430,25 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
if (padded) {
pblk_log_read_err(pblk, rqd);
+ bio_put(bio);
return -EINTR;
}
pad_distance = pblk_pad_distance(pblk, line);
ret = pblk_recov_pad_line(pblk, line, pad_distance);
- if (ret)
+ if (ret) {
+ bio_put(bio);
return ret;
+ }
padded = true;
+ bio_put(bio);
goto retry_rq;
}
pblk_get_packed_meta(pblk, rqd);
+ bio_put(bio);
+
for (i = 0; i < rqd->nr_ppas; i++) {
struct pblk_sec_meta *meta = pblk_get_meta(pblk, meta_list, i);
u64 lba = le64_to_cpu(meta->lba);
--
2.17.1
