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authorJianchao Wang <jianchao.w.wang@oracle.com>2018-05-04 16:01:57 +0800
committerKeith Busch <keith.busch@intel.com>2018-05-07 08:25:08 -0600
commit12d9f07022dcde261ad16e9a11f45096dc68b03c (patch)
treeed9a7b0d36e42fc0bb7fd2b3338ab9c6cc3b14a2
parent75bc37fefc4471e718ba8e651aa74673d4e0a9eb (diff)
nvme: fix use-after-free in nvme_free_ns_head
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@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <keith.busch@intel.com>
-rw-r--r--drivers/nvme/host/core.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index a3771c5729f5..2cbc378bc0d6 100644
--- 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);
int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
{
@@ -350,6 +351,7 @@ static void nvme_free_ns_head(struct kref *ref)
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);
}
@@ -2861,6 +2863,9 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
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);