From b76449ee75e21acfe9fa4c653d8598f191ed7d68 Mon Sep 17 00:00:00 2001 From: Dongliang Mu Date: Fri, 11 Nov 2022 13:49:49 +0800 Subject: fbdev: smscufx: fix error handling code in ufx_usb_probe The current error handling code in ufx_usb_probe have many unmatching issues, e.g., missing ufx_free_usb_list, destroy_modedb label should only include framebuffer_release, fb_dealloc_cmap only matches fb_alloc_cmap. My local syzkaller reports a memory leak bug: memory leak in ufx_usb_probe BUG: memory leak unreferenced object 0xffff88802f879580 (size 128): comm "kworker/0:7", pid 17416, jiffies 4295067474 (age 46.710s) hex dump (first 32 bytes): 80 21 7c 2e 80 88 ff ff 18 d0 d0 0c 80 88 ff ff .!|............. 00 d0 d0 0c 80 88 ff ff e0 ff ff ff 0f 00 00 00 ................ backtrace: [] kmalloc_trace+0x20/0x90 mm/slab_common.c:1045 [] kmalloc include/linux/slab.h:553 [inline] [] kzalloc include/linux/slab.h:689 [inline] [] ufx_alloc_urb_list drivers/video/fbdev/smscufx.c:1873 [inline] [] ufx_usb_probe+0x11c/0x15a0 drivers/video/fbdev/smscufx.c:1655 [] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [] call_driver_probe drivers/base/dd.c:560 [inline] [] really_probe+0x12d/0x390 drivers/base/dd.c:639 [] __driver_probe_device+0xbf/0x140 drivers/base/dd.c:778 [] driver_probe_device+0x2a/0x120 drivers/base/dd.c:808 [] __device_attach_driver+0xf7/0x150 drivers/base/dd.c:936 [] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:427 [] __device_attach+0x105/0x2d0 drivers/base/dd.c:1008 [] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:487 [] device_add+0x642/0xdc0 drivers/base/core.c:3517 [] usb_set_configuration+0x8ef/0xb80 drivers/usb/core/message.c:2170 [] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238 [] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293 [] call_driver_probe drivers/base/dd.c:560 [inline] [] really_probe+0x12d/0x390 drivers/base/dd.c:639 [] __driver_probe_device+0xbf/0x140 drivers/base/dd.c:778 Fix this bug by rewriting the error handling code in ufx_usb_probe. Reported-by: syzkaller Tested-by: Dongliang Mu Signed-off-by: Dongliang Mu Signed-off-by: Helge Deller --- drivers/video/fbdev/smscufx.c | 46 +++++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 15 deletions(-) (limited to 'drivers') diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c index 9343b7a4ac89..2ad6e98ce10d 100644 --- a/drivers/video/fbdev/smscufx.c +++ b/drivers/video/fbdev/smscufx.c @@ -1622,7 +1622,7 @@ static int ufx_usb_probe(struct usb_interface *interface, struct usb_device *usbdev; struct ufx_data *dev; struct fb_info *info; - int retval; + int retval = -ENOMEM; u32 id_rev, fpga_rev; /* usb initialization */ @@ -1654,15 +1654,17 @@ static int ufx_usb_probe(struct usb_interface *interface, if (!ufx_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) { dev_err(dev->gdev, "ufx_alloc_urb_list failed\n"); - goto e_nomem; + goto put_ref; } /* We don't register a new USB class. Our client interface is fbdev */ /* allocates framebuffer driver structure, not framebuffer memory */ info = framebuffer_alloc(0, &usbdev->dev); - if (!info) - goto e_nomem; + if (!info) { + dev_err(dev->gdev, "framebuffer_alloc failed\n"); + goto free_urb_list; + } dev->info = info; info->par = dev; @@ -1705,22 +1707,34 @@ static int ufx_usb_probe(struct usb_interface *interface, check_warn_goto_error(retval, "unable to find common mode for display and adapter"); retval = ufx_reg_set_bits(dev, 0x4000, 0x00000001); - check_warn_goto_error(retval, "error %d enabling graphics engine", retval); + if (retval < 0) { + dev_err(dev->gdev, "error %d enabling graphics engine", retval); + goto setup_modes; + } /* ready to begin using device */ atomic_set(&dev->usb_active, 1); dev_dbg(dev->gdev, "checking var"); retval = ufx_ops_check_var(&info->var, info); - check_warn_goto_error(retval, "error %d ufx_ops_check_var", retval); + if (retval < 0) { + dev_err(dev->gdev, "error %d ufx_ops_check_var", retval); + goto reset_active; + } dev_dbg(dev->gdev, "setting par"); retval = ufx_ops_set_par(info); - check_warn_goto_error(retval, "error %d ufx_ops_set_par", retval); + if (retval < 0) { + dev_err(dev->gdev, "error %d ufx_ops_set_par", retval); + goto reset_active; + } dev_dbg(dev->gdev, "registering framebuffer"); retval = register_framebuffer(info); - check_warn_goto_error(retval, "error %d register_framebuffer", retval); + if (retval < 0) { + dev_err(dev->gdev, "error %d register_framebuffer", retval); + goto reset_active; + } dev_info(dev->gdev, "SMSC UDX USB device /dev/fb%d attached. %dx%d resolution." " Using %dK framebuffer memory\n", info->node, @@ -1728,21 +1742,23 @@ static int ufx_usb_probe(struct usb_interface *interface, return 0; -error: - fb_dealloc_cmap(&info->cmap); -destroy_modedb: +reset_active: + atomic_set(&dev->usb_active, 0); +setup_modes: fb_destroy_modedb(info->monspecs.modedb); vfree(info->screen_base); fb_destroy_modelist(&info->modelist); +error: + fb_dealloc_cmap(&info->cmap); +destroy_modedb: framebuffer_release(info); +free_urb_list: + if (dev->urbs.count > 0) + ufx_free_urb_list(dev); put_ref: kref_put(&dev->kref, ufx_free); /* ref for framebuffer */ kref_put(&dev->kref, ufx_free); /* last ref from kref_init */ return retval; - -e_nomem: - retval = -ENOMEM; - goto put_ref; } static void ufx_usb_disconnect(struct usb_interface *interface) -- cgit v1.2.3