From: "Zhangjiantao (Kirin, nanjing)" water.zhangjiantao@huawei.com
when system is doing s4, the process of xhci_resume may be as below: 1、xhci_mem_cleanup 2、xhci_init->xhci_mem_init->xhci_mem_cleanup(when memory is not enough). xhci_mem_cleanup will be executed twice when system is out of memory. xhci->port_caps is freed in xhci_mem_cleanup,but it isn't set to NULL. It will be freed twice when xhci_mem_cleanup is called the second time.
We got following bug when system resumes from s4:
kernel BUG at mm/slub.c:309! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP CPU: 0 PID: 5929 Tainted: G S W 5.4.96-arm64-desktop #1 pc : __slab_free+0x5c/0x424 lr : kfree+0x30c/0x32c
Call trace: __slab_free+0x5c/0x424 kfree+0x30c/0x32c xhci_mem_cleanup+0x394/0x3cc xhci_mem_init+0x9ac/0x1070 xhci_init+0x8c/0x1d0 xhci_resume+0x1cc/0x5fc xhci_plat_resume+0x64/0x70 platform_pm_thaw+0x28/0x60 dpm_run_callback+0x54/0x24c device_resume+0xd0/0x200 async_resume+0x24/0x60 async_run_entry_fn+0x44/0x110 process_one_work+0x1f0/0x490 worker_thread+0x5c/0x450 kthread+0x158/0x160 ret_from_fork+0x10/0x24
Original patch that caused this issue was backported to 4.4 stable, so this should be backported to 4.4 stabe as well.
Fixes: cf0ee7c60c89 ("xhci: Fix memory leak when caching protocol extended capability PSI tables - take 2") Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Jiantao Zhang water.zhangjiantao@huawei.com Signed-off-by: Tao Xue xuetao09@huawei.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci-mem.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 2f6da35e7977..0e312066c5c6 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -1924,6 +1924,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci) xhci->hw_ports = NULL; xhci->rh_bw = NULL; xhci->ext_caps = NULL; + xhci->port_caps = NULL;
xhci->page_size = 0; xhci->page_shift = 0;