[ Upstream commit d8a1de3d5bb881507602bc02e004904828f88711 ]
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 juliana.rodrigueiro@intra2net.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/isdn/hardware/mISDN/hfcsusb.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c index 6f19530ba2a93..726fba452f5f6 100644 --- a/drivers/isdn/hardware/mISDN/hfcsusb.c +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c @@ -1701,13 +1701,23 @@ 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;