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authorKefeng Wang <wangkefeng.wang@huawei.com>2019-02-23 12:33:27 +0800
committerBen Hutchings <ben@decadent.org.uk>2019-09-23 21:12:17 +0100
commita79897227b81d588130813e83084b836733cb146 (patch)
treee85fe9e57723307055c415d7e6493e616a0504a9
parent16adebe264399fc1e8a78296426442b050ea0f54 (diff)
Bluetooth: hci_ldisc: Postpone HCI_UART_PROTO_READY bit set in hci_uart_set_proto()
commit 56897b217a1d0a91c9920cb418d6b3fe922f590a upstream. task A: task B: hci_uart_set_proto flush_to_ldisc - p->open(hu) -> h5_open //alloc h5 - receive_buf - set_bit HCI_UART_PROTO_READY - tty_port_default_receive_buf - hci_uart_register_dev - tty_ldisc_receive_buf - hci_uart_tty_receive - test_bit HCI_UART_PROTO_READY - h5_recv - clear_bit HCI_UART_PROTO_READY while() { - p->open(hu) -> h5_close //free h5 - h5_rx_3wire_hdr - h5_reset() //use-after-free } It could use ioctl to set hci uart proto, but there is a use-after-free issue when hci_uart_register_dev() fail in hci_uart_set_proto(), see stack above, fix this by setting HCI_UART_PROTO_READY bit only when hci_uart_register_dev() return success. Reported-by: syzbot+899a33dc0fa0dbaf06a6@syzkaller.appspotmail.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Jeremy Cline <jcline@redhat.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/bluetooth/hci_ldisc.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index d1f95075c23b..d90b3d04ef31 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -477,15 +477,14 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id)
return err;
hu->proto = p;
- set_bit(HCI_UART_PROTO_READY, &hu->flags);
err = hci_uart_register_dev(hu);
if (err) {
- clear_bit(HCI_UART_PROTO_READY, &hu->flags);
p->close(hu);
return err;
}
+ set_bit(HCI_UART_PROTO_READY, &hu->flags);
return 0;
}