On 8/13/22 00:03, Bart Van Assche wrote:
Fix the following use-after-free complaint triggered by blktests nvme/004:
BUG: KASAN: user-memory-access in blk_mq_complete_request_remote+0xac/0x350
Read of size 4 at addr 0000607bd1835943 by task kworker/13:1/460
Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop]
Call Trace:
show_stack+0x52/0x58
dump_stack_lvl+0x49/0x5e
print_report.cold+0x36/0x1e2
kasan_report+0xb9/0xf0
__asan_load4+0x6b/0x80
blk_mq_complete_request_remote+0xac/0x350
nvme_loop_queue_response+0x1df/0x275 [nvme_loop]
__nvmet_req_complete+0x132/0x4f0 [nvmet]
nvmet_req_complete+0x15/0x40 [nvmet]
nvmet_execute_io_connect+0x18a/0x1f0 [nvmet]
nvme_loop_execute_work+0x20/0x30 [nvme_loop]
process_one_work+0x56e/0xa70
worker_thread+0x2d1/0x640
kthread+0x183/0x1c0
ret_from_fork+0x1f/0x30
Cc: stable@xxxxxxxxxxxxxxx
Fixes: a07b4970f464 ("nvmet: add a generic NVMe target")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/nvme/target/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index a1345790005f..7f4083cf953a 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -735,6 +735,8 @@ static void nvmet_set_error(struct nvmet_req *req, u16 status)
static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
{
+ struct nvmet_ns *ns = req->ns;
+
if (!req->sq->sqhd_disabled)
nvmet_update_sq_head(req);
req->cqe->sq_id = cpu_to_le16(req->sq->qid);
@@ -745,9 +747,9 @@ static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
trace_nvmet_req_complete(req);
- if (req->ns)
- nvmet_put_namespace(req->ns);
req->ops->queue_response(req);
+ if (ns)
+ nvmet_put_namespace(ns);
Why did the put change position?
I'm not exactly clear what was used-after-free here..
}
void nvmet_req_complete(struct nvmet_req *req, u16 status)
