From a0d57a552b836206ad7705a1060e6e1ce5a38203 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Fri, 26 Jul 2019 16:27:36 +0800 Subject: isdn: mISDN: hfcsusb: Fix possible null-pointer dereferences in start_isoc_chain() In start_isoc_chain(), usb_alloc_urb() on line 1392 may fail and return NULL. At this time, fifo->iso[i].urb is assigned to NULL. Then, fifo->iso[i].urb is used at some places, such as: LINE 1405: fill_isoc_urb(fifo->iso[i].urb, ...) urb->number_of_packets = num_packets; urb->transfer_flags = URB_ISO_ASAP; urb->actual_length = 0; urb->interval = interval; LINE 1416: fifo->iso[i].urb->... LINE 1419: fifo->iso[i].urb->... Thus, possible null-pointer dereferences may occur. To fix these bugs, "continue" is added to avoid using fifo->iso[i].urb when it is NULL. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai Signed-off-by: David S. Miller --- drivers/isdn/hardware/mISDN/hfcsusb.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/isdn/hardware/mISDN/hfcsusb.c') diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c index 0e224232f746..8fb7c5dea07f 100644 --- a/drivers/isdn/hardware/mISDN/hfcsusb.c +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c @@ -1394,6 +1394,7 @@ start_isoc_chain(struct usb_fifo *fifo, int num_packets_per_urb, printk(KERN_DEBUG "%s: %s: alloc urb for fifo %i failed", hw->name, __func__, fifo->fifonum); + continue; } fifo->iso[i].owner_fifo = (struct usb_fifo *) fifo; fifo->iso[i].indx = i; -- cgit v1.2.3-59-g8ed1b From d8a1de3d5bb881507602bc02e004904828f88711 Mon Sep 17 00:00:00 2001 From: Juliana Rodrigueiro Date: Wed, 31 Jul 2019 15:17:23 +0200 Subject: isdn: hfcsusb: Fix mISDN driver crash caused by transfer buffer on the stack Since linux 4.9 it is not possible to use buffers on the stack for DMA transfers. During usb probe the driver crashes with "transfer buffer is on stack" message. This fix k-allocates a buffer to be used on "read_reg_atomic", which is a macro that calls "usb_control_msg" under the hood. Kernel 4.19 backtrace: usb_hcd_submit_urb+0x3e5/0x900 ? sched_clock+0x9/0x10 ? log_store+0x203/0x270 ? get_random_u32+0x6f/0x90 ? cache_alloc_refill+0x784/0x8a0 usb_submit_urb+0x3b4/0x550 usb_start_wait_urb+0x4e/0xd0 usb_control_msg+0xb8/0x120 hfcsusb_probe+0x6bc/0xb40 [hfcsusb] usb_probe_interface+0xc2/0x260 really_probe+0x176/0x280 driver_probe_device+0x49/0x130 __driver_attach+0xa9/0xb0 ? driver_probe_device+0x130/0x130 bus_for_each_dev+0x5a/0x90 driver_attach+0x14/0x20 ? driver_probe_device+0x130/0x130 bus_add_driver+0x157/0x1e0 driver_register+0x51/0xe0 usb_register_driver+0x5d/0x120 ? 0xf81ed000 hfcsusb_drv_init+0x17/0x1000 [hfcsusb] do_one_initcall+0x44/0x190 ? free_unref_page_commit+0x6a/0xd0 do_init_module+0x46/0x1c0 load_module+0x1dc1/0x2400 sys_init_module+0xed/0x120 do_fast_syscall_32+0x7a/0x200 entry_SYSENTER_32+0x6b/0xbe Signed-off-by: Juliana Rodrigueiro Signed-off-by: David S. Miller --- drivers/isdn/hardware/mISDN/hfcsusb.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/isdn/hardware/mISDN/hfcsusb.c') diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c index 8fb7c5dea07f..008a74a1ed44 100644 --- a/drivers/isdn/hardware/mISDN/hfcsusb.c +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c @@ -1693,13 +1693,23 @@ hfcsusb_stop_endpoint(struct hfcsusb *hw, int channel) static int setup_hfcsusb(struct hfcsusb *hw) { + void *dmabuf = kmalloc(sizeof(u_char), GFP_KERNEL); u_char b; + int ret; if (debug & DBG_HFC_CALL_TRACE) printk(KERN_DEBUG "%s: %s\n", hw->name, __func__); + if (!dmabuf) + return -ENOMEM; + + ret = read_reg_atomic(hw, HFCUSB_CHIP_ID, dmabuf); + + memcpy(&b, dmabuf, sizeof(u_char)); + kfree(dmabuf); + /* check the chip id */ - if (read_reg_atomic(hw, HFCUSB_CHIP_ID, &b) != 1) { + if (ret != 1) { printk(KERN_DEBUG "%s: %s: cannot read chip id\n", hw->name, __func__); return 1; -- cgit v1.2.3-59-g8ed1b