| Message ID | 20210804143005.439-1-paskripkin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net,v2] net: pegasus: fix uninit-value in get_interrupt_interval | expand |
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Wed, 4 Aug 2021 17:30:05 +0300 you 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. > > [...] Here is the summary with links: - [net,v2] net: pegasus: fix uninit-value in get_interrupt_interval https://git.kernel.org/netdev/net/c/af35fc37354c You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c index f18b03be1..652e9fcf0 100644 --- a/drivers/net/usb/pegasus.c +++ b/drivers/net/usb/pegasus.c @@ -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;
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> --- Changes in v2: Rebased on top of -net --- drivers/net/usb/pegasus.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)