Messages in this thread | | | Subject | Re: [PATCH] net: pegasus: fix uninit-value in get_interrupt_interval | From | Pavel Skripkin <> | Date | Tue, 3 Aug 2021 01:18:37 +0300 |
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On 8/2/21 11:07 PM, Petko Manolov wrote: > On 21-08-01 22:35:13, Pavel Skripkin wrote: >> On Sun, 1 Aug 2021 15:36:27 +0300 >> Petko Manolov <petkan@nucleusys.com> wrote: >> >> > On 21-07-31 00:44:11, Pavel Skripkin wrote: >> > > Syzbot reported uninit value pegasus_probe(). The problem was in missing >> > > error handling. >> > > >> > > get_interrupt_interval() internally calls read_eprom_word() which can fail >> > > in some cases. For example: failed to receive usb control message. These >> > > cases should be handled to prevent uninit value bug, since >> > > read_eprom_word() will not initialize passed stack variable in case of >> > > internal failure. >> > >> > Well, this is most definitelly a bug. >> > >> > ACK! >> > >> > >> > Petko >> > >> > >> >> Thank you, Petko! >> >> >> BTW: I found a lot uses of {get,set}_registers without error checking. I >> think, some of them could be fixed easily (like in enable_eprom_write), but, I >> guess, disable_eprom_write is not so easy. For example, if we cannot disable >> eprom should we retry? If not, will device get in some unexpected state? >> >> Im not familiar with this device, but I can prepare a patch to wrap all these >> calls with proper error checking > > Here goes a preliminary patch that should apply on top of your, maybe with just > a few warnings. This is a review only diff, not the real patch. It's against > 5.14-rc4. > > I am mildly curious why syzbot didn't catch the same type of bug in > enable_net_traffic() and setup_pegasus_II() for example. > > > Petko > > --- > > diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c > index 9a907182569c..eafbe8107907 100644 > --- a/drivers/net/usb/pegasus.c > +++ b/drivers/net/usb/pegasus.c > @@ -26,6 +26,8 @@ > * ... > * v0.9.3 simplified [get|set]_register(s), async update registers > * logic revisited, receive skb_pool removed. > + * v1.0.1 add error checking for set_register(s)(), see if calling > + * get_registers() has failed and print a message accordingly. > */ > > #include <linux/sched.h> > @@ -45,7 +47,7 @@ > /* > * Version Information > */ > -#define DRIVER_VERSION "v0.9.3 (2013/04/25)" > +#define DRIVER_VERSION "v1.0.1 (2021/08/01)" > #define DRIVER_AUTHOR "Petko Manolov <petkan@nucleusys.com>" > #define DRIVER_DESC "Pegasus/Pegasus II USB Ethernet driver" > > @@ -132,9 +134,15 @@ static int get_registers(pegasus_t *pegasus, __u16 indx, __u16 size, void *data) > static int set_registers(pegasus_t *pegasus, __u16 indx, __u16 size, > const void *data) > { > - return usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REGS, > + int ret; > + > + ret = usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REGS, > PEGASUS_REQT_WRITE, 0, indx, data, size, > 1000, GFP_NOIO); > + if (ret < 0) > + netif_dbg(pegasus, drv, pegasus->net, "%s failed with %d\n", __func__, ret); > + > + return ret; > } > > /* > @@ -145,10 +153,15 @@ static int set_registers(pegasus_t *pegasus, __u16 indx, __u16 size, > static int set_register(pegasus_t *pegasus, __u16 indx, __u8 data) > { > void *buf = &data; > + int ret; > > - return usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REG, > + ret = usb_control_msg_send(pegasus->usb, 0, PEGASUS_REQ_SET_REG, > PEGASUS_REQT_WRITE, data, indx, buf, 1, > 1000, GFP_NOIO); > + if (ret < 0) > + netif_dbg(pegasus, drv, pegasus->net, "%s failed with %d\n", __func__, ret); > + > + return ret; > } > > static int update_eth_regs_async(pegasus_t *pegasus) > @@ -188,10 +201,9 @@ static int update_eth_regs_async(pegasus_t *pegasus) > > static int __mii_op(pegasus_t *p, __u8 phy, __u8 indx, __u16 *regd, __u8 cmd) > { > - int i; > - __u8 data[4] = { phy, 0, 0, indx }; > + int i, ret = -ETIMEDOUT; > __le16 regdi; > - int ret = -ETIMEDOUT; > + __u8 data[4] = { phy, 0, 0, indx }; > > if (cmd & PHY_WRITE) { > __le16 *t = (__le16 *) & data[1]; > @@ -211,8 +223,9 @@ static int __mii_op(pegasus_t *p, __u8 phy, __u8 indx, __u16 *regd, __u8 cmd) > goto fail; > if (cmd & PHY_READ) { > ret = get_registers(p, PhyData, 2, ®di); > + if (ret < 0) > + goto fail; > *regd = le16_to_cpu(regdi); > - return ret; > } > return 0; > fail: > @@ -235,9 +248,13 @@ static int write_mii_word(pegasus_t *pegasus, __u8 phy, __u8 indx, __u16 *regd) > static int mdio_read(struct net_device *dev, int phy_id, int loc) > { > pegasus_t *pegasus = netdev_priv(dev); > + int ret; > u16 res; > > - read_mii_word(pegasus, phy_id, loc, &res); > + ret = read_mii_word(pegasus, phy_id, loc, &res); > + if (ret < 0) > + return ret; > + > return (int)res; > } > > @@ -251,10 +268,9 @@ static void mdio_write(struct net_device *dev, int phy_id, int loc, int val) > > static int read_eprom_word(pegasus_t *pegasus, __u8 index, __u16 *retdata) > { > - int i; > - __u8 tmp = 0; > + int ret, i; > __le16 retdatai; > - int ret; > + __u8 tmp = 0; > > set_register(pegasus, EpromCtrl, 0); > set_register(pegasus, EpromOffset, index); > @@ -262,21 +278,25 @@ static int read_eprom_word(pegasus_t *pegasus, __u8 index, __u16 *retdata) > > for (i = 0; i < REG_TIMEOUT; i++) { > ret = get_registers(pegasus, EpromCtrl, 1, &tmp); > + if (ret < 0) > + goto fail; > if (tmp & EPROM_DONE) > break; > - if (ret == -ESHUTDOWN) > - goto fail; > } > - if (i >= REG_TIMEOUT) > + if (i >= REG_TIMEOUT) { > + ret = -ETIMEDOUT; > goto fail; > + } > > ret = get_registers(pegasus, EpromData, 2, &retdatai); > + if (ret < 0) > + goto fail; > *retdata = le16_to_cpu(retdatai); > return ret; > > fail: > - netif_warn(pegasus, drv, pegasus->net, "%s failed\n", __func__); > - return -ETIMEDOUT; > + netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__); > + return ret; > } > > #ifdef PEGASUS_WRITE_EEPROM > @@ -324,10 +344,10 @@ static int write_eprom_word(pegasus_t *pegasus, __u8 index, __u16 data) > return ret; > > fail: > - netif_warn(pegasus, drv, pegasus->net, "%s failed\n", __func__); > + netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__); > return -ETIMEDOUT; > } > -#endif /* PEGASUS_WRITE_EEPROM */ > +#endif /* PEGASUS_WRITE_EEPROM */ > > static inline int get_node_id(pegasus_t *pegasus, u8 *id) > { > @@ -367,19 +387,21 @@ static void set_ethernet_addr(pegasus_t *pegasus) > return; > err: > eth_hw_addr_random(pegasus->net); > - dev_info(&pegasus->intf->dev, "software assigned MAC address.\n"); > + netif_dbg(pegasus, drv, pegasus->net, "software assigned MAC address.\n"); > > return; > }
Not related to the patch, but, maybe, we should remove this return?
> > static inline int reset_mac(pegasus_t *pegasus) > { > + int ret, i; > __u8 data = 0x8; > - int i; > > set_register(pegasus, EthCtrl1, data); > for (i = 0; i < REG_TIMEOUT; i++) { > - get_registers(pegasus, EthCtrl1, 1, &data); > + ret = get_registers(pegasus, EthCtrl1, 1, &data); > + if (ret < 0) > + goto fail; > if (~data & 0x08) { > if (loopback) > break; > @@ -402,22 +424,29 @@ static inline int reset_mac(pegasus_t *pegasus) > } > if (usb_dev_id[pegasus->dev_index].vendor == VENDOR_ELCON) { > __u16 auxmode; > - read_mii_word(pegasus, 3, 0x1b, &auxmode); > + ret = read_mii_word(pegasus, 3, 0x1b, &auxmode); > + if (ret < 0) > + goto fail; > auxmode |= 4; > write_mii_word(pegasus, 3, 0x1b, &auxmode); > } > > return 0; > +fail: > + netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__); > + return ret; > } > > static int enable_net_traffic(struct net_device *dev, struct usb_device *usb) > { > - __u16 linkpart; > - __u8 data[4]; > pegasus_t *pegasus = netdev_priv(dev); > int ret; > + __u16 linkpart; > + __u8 data[4]; > > - read_mii_word(pegasus, pegasus->phy, MII_LPA, &linkpart); > + ret = read_mii_word(pegasus, pegasus->phy, MII_LPA, &linkpart); > + if (ret < 0) > + goto fail; > data[0] = 0xc8; /* TX & RX enable, append status, no CRC */ > data[1] = 0; > if (linkpart & (ADVERTISE_100FULL | ADVERTISE_10FULL)) > @@ -435,11 +464,16 @@ static int enable_net_traffic(struct net_device *dev, struct usb_device *usb) > usb_dev_id[pegasus->dev_index].vendor == VENDOR_LINKSYS2 || > usb_dev_id[pegasus->dev_index].vendor == VENDOR_DLINK) { > u16 auxmode; > - read_mii_word(pegasus, 0, 0x1b, &auxmode); > + ret = read_mii_word(pegasus, 0, 0x1b, &auxmode); > + if (ret < 0) > + goto fail; > auxmode |= 4; > write_mii_word(pegasus, 0, 0x1b, &auxmode); > } > > + return 0; > +fail: > + netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__); > return ret; > } > > @@ -447,9 +481,9 @@ static void read_bulk_callback(struct urb *urb) > { > pegasus_t *pegasus = urb->context; > struct net_device *net; > + u8 *buf = urb->transfer_buffer; > int rx_status, count = urb->actual_length; > int status = urb->status; > - u8 *buf = urb->transfer_buffer; > __u16 pkt_len; > > if (!pegasus) > @@ -1049,6 +1083,7 @@ static __u8 mii_phy_probe(pegasus_t *pegasus) > > static inline void setup_pegasus_II(pegasus_t *pegasus) > { > + int ret; > __u8 data = 0xa5; > > set_register(pegasus, Reg1d, 0); > @@ -1060,7 +1095,9 @@ static inline void setup_pegasus_II(pegasus_t *pegasus) > set_register(pegasus, Reg7b, 2); > > set_register(pegasus, 0x83, data); > - get_registers(pegasus, 0x83, 1, &data); > + ret = get_registers(pegasus, 0x83, 1, &data); > + if (ret < 0) > + goto fail; > > if (data == 0xa5) > pegasus->chip = 0x8513; > @@ -1075,6 +1112,8 @@ static inline void setup_pegasus_II(pegasus_t *pegasus) > set_register(pegasus, Reg81, 6); > else > set_register(pegasus, Reg81, 2); > +fail: > + netif_dbg(pegasus, drv, pegasus->net, "%s failed\n", __func__); > } > > static void check_carrier(struct work_struct *work) >
Looks good to me.
Build test didn't generate any warnings (tested on top of v5.14-rc4 with yours and mine patches applied). Smatch didn't generate any warnings as well.
I found two more places, where read_mii_word() is used without error checking: pegasus_ioctl() and mii_phy_probe(). If I understand correctly, mii_phy_probe() is more dangerous one, since it's used in ->probe().
With regards, Pavel Skripkin
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