From: Pavel Skripkin paskripkin@gmail.com
[ Upstream commit af35fc37354cda3c9c8cc4961b1d24bdc9d27903 ]
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: 1da177e4c3f4 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/pegasus.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c index 4f505eb4f422..a7b1df01e0f7 100644 --- a/drivers/net/usb/pegasus.c +++ b/drivers/net/usb/pegasus.c @@ -755,12 +755,16 @@ 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) { @@ -775,6 +779,8 @@ static inline void get_interrupt_interval(pegasus_t *pegasus) } } pegasus->intr_interval = interval; + + return 0; }
static void set_carrier(struct net_device *net) @@ -1190,7 +1196,9 @@ 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;