4.16-stable review patch. If anyone has any objections, please let me know.
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From: Jianchao Wang jianchao.w.wang@oracle.com
[ 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@oracle.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch keith.busch@intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);