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net: pegasus: fix uninit-value in get_interrupt_interval

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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.

Fail log:

BUG: KMSAN: uninit-value in get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
BUG: KMSAN: uninit-value in pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
CPU: 1 PID: 825 Comm: kworker/1:1 Not tainted 5.12.0-rc6-syzkaller #0
...
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
 pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
....

Local variable ----data.i@pegasus_probe created at:
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152

Reported-and-tested-by: syzbot+02c9f70f3afae308464a@syzkaller.appspotmail.com
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20210804143005.439-1-paskripkin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Pavel Skripkin 2021-08-04 17:30:05 +03:00 committed by Jakub Kicinski
parent ae03d189ba
commit af35fc3735
1 changed files with 11 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
drivers/net/usb/pegasus.c
View file

@ -744,12 +744,16 @@ static inline void disable_net_traffic(pegasus_t *pegasus)
set_registers(pegasus, EthCtrl0, sizeof(tmp), &tmp);
}
static inline void get_interrupt_interval(pegasus_t *pegasus)
static inline int get_interrupt_interval(pegasus_t *pegasus)
{
u16 data;
u8 interval;
int ret;
ret = read_eprom_word(pegasus, 4, &data);
if (ret < 0)
return ret;
read_eprom_word(pegasus, 4, &data);
interval = data >> 8;
if (pegasus->usb->speed != USB_SPEED_HIGH) {
if (interval < 0x80) {
@ -764,6 +768,8 @@ static inline void get_interrupt_interval(pegasus_t *pegasus)
}
}
pegasus->intr_interval = interval;
return 0;
}
static void set_carrier(struct net_device *net)
@ -1165,7 +1171,9 @@ static int pegasus_probe(struct usb_interface *intf,
| NETIF_MSG_PROBE | NETIF_MSG_LINK);
pegasus->features = usb_dev_id[dev_index].private;
get_interrupt_interval(pegasus);
res = get_interrupt_interval(pegasus);
if (res)
goto out2;
if (reset_mac(pegasus)) {
dev_err(&intf->dev, "can't reset MAC\n");
res = -EIO;