Re: [PATCH] lightnvm: pblk: fix use-after-free bug

From: Matias BjÃrling
Date: Sat Dec 22 2018 - 13:30:25 EST


On 12/22/18 8:39 AM, Gustavo A. R. Silva wrote:
Remove one of the calls to function bio_put(), so *bio* is only
freed once.

Notice that bio is being dereferenced in bio_put(), hence leading to
a use-after-free bug once *bio* has already been freed.

Addresses-Coverity-ID: 1475952 ("Use after free")
Fixes: 55d8ec35398e ("lightnvm: pblk: support packed metadata")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/lightnvm/pblk-recovery.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 3fcf062d752c..5ee20da7bdb3 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -418,7 +418,6 @@ 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;
}


Thanks Gustavo. I missed that one.

Jens, if possible could you please pick this up?

Happy holidays!