[PATCH] NFC: nci: fix memory leak in nci_allocate_device

[PATCH] NFC: nci: fix memory leak in nci_allocate_device

[Dongliang Mu]

nfcmrvl_disconnect fails to free the hci_dev field in struct nci_dev.
Fix this by freeing hci_dev in nci_free_device.

BUG: memory leak
unreferenced object 0xffff888111ea6800 (size 1024):
  comm "kworker/1:0", pid 19, jiffies 4294942308 (age 13.580s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 60 fd 0c 81 88 ff ff  .........`......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000004bc25d43>] kmalloc include/linux/slab.h:552 [inline]
    [<000000004bc25d43>] kzalloc include/linux/slab.h:682 [inline]
    [<000000004bc25d43>] nci_hci_allocate+0x21/0xd0 net/nfc/nci/hci.c:784
    [<00000000c59cff92>] nci_allocate_device net/nfc/nci/core.c:1170 [inline]
    [<00000000c59cff92>] nci_allocate_device+0x10b/0x160 net/nfc/nci/core.c:1132
    [<00000000006e0a8e>] nfcmrvl_nci_register_dev+0x10a/0x1c0 drivers/nfc/nfcmrvl/main.c:153
    [<000000004da1b57e>] nfcmrvl_probe+0x223/0x290 drivers/nfc/nfcmrvl/usb.c:345
    [<00000000d506aed9>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554
    [<00000000f5009125>] driver_probe_device+0x84/0x100 drivers/base/dd.c:740
    [<000000000ce658ca>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:846
    [<000000007067d05f>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
    [<00000000f8e13372>] __device_attach+0x122/0x250 drivers/base/dd.c:914
    [<000000009cf68860>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
    [<00000000359c965a>] device_add+0x5be/0xc30 drivers/base/core.c:3109
    [<00000000086e4bd3>] usb_set_configuration+0x9d9/0xb90 drivers/usb/core/message.c:2164
    [<00000000ca036872>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
    [<00000000d40d36f6>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554

Reported-by: syzbot+19bcfc64a8df1318d1c3@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 include/net/nfc/nci_core.h | 1 +
 net/nfc/nci/core.c         | 1 +
 net/nfc/nci/hci.c          | 5 +++++
 3 files changed, 7 insertions(+)

diff --git a/include/net/nfc/nci_core.h b/include/net/nfc/nci_core.h
index bd76e8e082c0..aa2e0f169015 100644
--- a/include/net/nfc/nci_core.h
+++ b/include/net/nfc/nci_core.h
@@ -298,6 +298,7 @@ int nci_nfcc_loopback(struct nci_dev *ndev, void *data, size_t data_len,
 		      struct sk_buff **resp);
 
 struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev);
+void nci_hci_allocate(struct nci_dev *ndev);
 int nci_hci_send_event(struct nci_dev *ndev, u8 gate, u8 event,
 		       const u8 *param, size_t param_len);
 int nci_hci_send_cmd(struct nci_dev *ndev, u8 gate,
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 9a585332ea84..da7fe9db1b00 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1191,6 +1191,7 @@ EXPORT_SYMBOL(nci_allocate_device);
 void nci_free_device(struct nci_dev *ndev)
 {
 	nfc_free_device(ndev->nfc_dev);
+	nci_hci_deallocate(ndev);
 	kfree(ndev);
 }
 EXPORT_SYMBOL(nci_free_device);
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index 6b275a387a92..96865142104f 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -792,3 +792,8 @@ struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev)
 
 	return hdev;
 }
+
+void nci_hci_deallocate(struct nci_dev *ndev)
+{
+	kfree(ndev->hci_dev);
+}
-- 
2.25.1

Re: [PATCH] NFC: nci: fix memory leak in nci_allocate_device

[Jakub Kicinski]

On Fri, 14 May 2021 15:42:48 +0800 Dongliang Mu wrote:
>  struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev);
>                 void nci_hci_allocate(struct nci_dev *ndev);

This patch does not build.

Re: [PATCH] NFC: nci: fix memory leak in nci_allocate_device

[慕冬亮]

On Sat, May 15, 2021 at 3:32 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Fri, 14 May 2021 15:42:48 +0800 Dongliang Mu wrote:
> >  struct nci_hci_dev *nci_hci_allocate(struct nci_dev *ndev);
> >                 void nci_hci_allocate(struct nci_dev *ndev);
>
> This patch does not build.

Sorry, it's my bad. This function should be nci_hci_deallocate. I will
send v2 now.