From b31d9d6d7abbf6483b871b6370bc31c930d53f54 Mon Sep 17 00:00:00 2001
From: "Zhangjiantao (Kirin, nanjing)" <water.zhangjiantao@huawei.com>
Date: Thu, 17 Jun 2021 18:03:54 +0300
Subject: [PATCH] xhci: solve a double free problem while doing s4
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Git-commit: b31d9d6d7abbf6483b871b6370bc31c930d53f54
Patch-mainline: v5.14-rc1
References: git-fixes
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>
Link: https://lore.kernel.org/r/20210617150354.1512157-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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;
--
2.26.2