4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
[ Upstream commit 12d9f07022dcde261ad16e9a11f45096dc68b03c ]
Currently only nvme_ctrl will take a reference counter of
nvme_subsystem, nvme_ns_head also needs it. Otherwise
nvme_free_ns_head will access the nvme_subsystem.ns_ida
which has been freed by __nvme_release_subsystem after all the
reference of nvme_subsystem have been released by nvme_free_ctrl.
This could cause memory corruption.
BUG: KASAN: use-after-free in radix_tree_next_chunk+0x9f/0x4b0
Read of size 8 at addr ffff88036494d2e8 by task fio/1815
CPU: 1 PID: 1815 Comm: fio Kdump: loaded Tainted: G W 4.17.0-rc1+ #18
Hardware name: LENOVO 10MLS0E339/3106, BIOS M1AKT22A 06/27/2017
Call Trace:
dump_stack+0x91/0xeb
print_address_description+0x6b/0x290
kasan_report+0x261/0x360
radix_tree_next_chunk+0x9f/0x4b0
ida_remove+0x8b/0x180
ida_simple_remove+0x26/0x40
nvme_free_ns_head+0x58/0xc0
__blkdev_put+0x30a/0x3a0
blkdev_close+0x44/0x50
__fput+0x184/0x380
task_work_run+0xaf/0xe0
do_exit+0x501/0x1440
do_group_exit+0x89/0x140
__x64_sys_exit_group+0x28/0x30
do_syscall_64+0x72/0x230
Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvme/host/core.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -99,6 +99,7 @@ static struct class *nvme_subsys_class;
static void nvme_ns_remove(struct nvme_ns *ns);
static int nvme_revalidate_disk(struct gendisk *disk);
+static void nvme_put_subsystem(struct nvme_subsystem *subsys);
static __le32 nvme_get_log_dw10(u8 lid, size_t size)
{
@@ -353,6 +354,7 @@ static void nvme_free_ns_head(struct kre
ida_simple_remove(&head->subsys->ns_ida, head->instance);
list_del_init(&head->entry);
cleanup_srcu_struct(&head->srcu);
+ nvme_put_subsystem(head->subsys);
kfree(head);
}
@@ -2843,6 +2845,9 @@ static struct nvme_ns_head *nvme_alloc_n
goto out_cleanup_srcu;
list_add_tail(&head->entry, &ctrl->subsys->nsheads);
+
+ kref_get(&ctrl->subsys->ref);
+
return head;
out_cleanup_srcu:
cleanup_srcu_struct(&head->srcu);
