[PATCH v3] btusb: fix wrong use of PTR_ERR()

From: Adam Lee
Date: Tue Jul 09 2013 - 22:02:27 EST


PTR_ERR() returns a signed long type value which is limited by IS_ERR(),
it must be a negative number whose range is [-MAX_ERRNO, 0).

The bug here returns negative numbers as error codes, then check it by
"if (ret < 0)", but -PTR_ERR() is actually positive. The wrong use here
leads to failure as below, even panic.

[ 12.958920] Bluetooth: hci0 command 0xfc8e tx timeout
[ 14.961765] Bluetooth: hci0 command 0xfc8e tx timeout
[ 16.964688] Bluetooth: hci0 command 0xfc8e tx timeout
[ 20.954501] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 22.957358] Bluetooth: hci0 command 0xfc8e tx timeout
[ 30.948922] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 32.951780] Bluetooth: hci0 command 0xfc8e tx timeout
[ 40.943359] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 42.946219] Bluetooth: hci0 command 0xfc8e tx timeout
[ 50.937812] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 52.940670] Bluetooth: hci0 command 0xfc8e tx timeout
[ 60.932236] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 62.935092] Bluetooth: hci0 command 0xfc8e tx timeout
[ 70.926688] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 72.929545] Bluetooth: hci0 command 0xfc8e tx timeout
[ 80.921111] Bluetooth: hci0 sending Intel patch command (0xfc8e) failed (-110)
[ 82.923969] Bluetooth: hci0 command 0xfc2f tx timeout
[ 90.915542] Bluetooth: hci0 sending Intel patch command (0xfc2f) failed (-110)
[ 92.918406] Bluetooth: hci0 command 0xfc11 tx timeout
[ 100.909955] Bluetooth: hci0 sending Intel patch command (0xfc11) failed (-110)
[ 102.912858] Bluetooth: hci0 command 0xfc60 tx timeout
[ 110.904394] Bluetooth: hci0 sending Intel patch command (0xfc60) failed (-110)
[ 112.907293] Bluetooth: hci0 command 0xfc11 tx timeout
[ 120.898831] Bluetooth: hci0 exiting Intel manufacturer mode failed (-110)
[ 120.904757] bluetoothd[1030]: segfault at 4 ip 00007f8b2eb55236 sp 00007fff53ff6920 error 4 in bluetoothd[7f8b2eaff000+cb000]

Signed-off-by: Adam Lee <adam.lee@xxxxxxxxxxxxx>
---
drivers/bluetooth/btusb.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 7a7e5f8..23df968 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1092,7 +1092,7 @@ static int btusb_setup_intel_patching(struct hci_dev *hdev,
if (IS_ERR(skb)) {
BT_ERR("%s sending Intel patch command (0x%4.4x) failed (%ld)",
hdev->name, cmd->opcode, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}

/* It ensures that the returned event matches the event data read from
@@ -1144,7 +1144,7 @@ static int btusb_setup_intel(struct hci_dev *hdev)
if (IS_ERR(skb)) {
BT_ERR("%s sending initial HCI reset command failed (%ld)",
hdev->name, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}
kfree_skb(skb);

@@ -1158,7 +1158,7 @@ static int btusb_setup_intel(struct hci_dev *hdev)
if (IS_ERR(skb)) {
BT_ERR("%s reading Intel fw version command failed (%ld)",
hdev->name, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}

if (skb->len != sizeof(*ver)) {
@@ -1216,7 +1216,7 @@ static int btusb_setup_intel(struct hci_dev *hdev)
BT_ERR("%s entering Intel manufacturer mode failed (%ld)",
hdev->name, PTR_ERR(skb));
release_firmware(fw);
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}

if (skb->data[0]) {
@@ -1273,7 +1273,7 @@ static int btusb_setup_intel(struct hci_dev *hdev)
if (IS_ERR(skb)) {
BT_ERR("%s exiting Intel manufacturer mode failed (%ld)",
hdev->name, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}
kfree_skb(skb);

@@ -1289,7 +1289,7 @@ exit_mfg_disable:
if (IS_ERR(skb)) {
BT_ERR("%s exiting Intel manufacturer mode failed (%ld)",
hdev->name, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}
kfree_skb(skb);

@@ -1307,7 +1307,7 @@ exit_mfg_deactivate:
if (IS_ERR(skb)) {
BT_ERR("%s exiting Intel manufacturer mode failed (%ld)",
hdev->name, PTR_ERR(skb));
- return -PTR_ERR(skb);
+ return PTR_ERR(skb);
}
kfree_skb(skb);

--
1.8.3.2
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