From: Dongliang Mu dzm91@hust.edu.cn
commit b76449ee75e21acfe9fa4c653d8598f191ed7d68 upstream.
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: [<ffffffff814c99a0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1045 [<ffffffff824d219c>] kmalloc include/linux/slab.h:553 [inline] [<ffffffff824d219c>] kzalloc include/linux/slab.h:689 [inline] [<ffffffff824d219c>] ufx_alloc_urb_list drivers/video/fbdev/smscufx.c:1873 [inline] [<ffffffff824d219c>] ufx_usb_probe+0x11c/0x15a0 drivers/video/fbdev/smscufx.c:1655 [<ffffffff82d17927>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [<ffffffff82712f0d>] call_driver_probe drivers/base/dd.c:560 [inline] [<ffffffff82712f0d>] really_probe+0x12d/0x390 drivers/base/dd.c:639 [<ffffffff8271322f>] __driver_probe_device+0xbf/0x140 drivers/base/dd.c:778 [<ffffffff827132da>] driver_probe_device+0x2a/0x120 drivers/base/dd.c:808 [<ffffffff82713c27>] __device_attach_driver+0xf7/0x150 drivers/base/dd.c:936 [<ffffffff82710137>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:427 [<ffffffff827136b5>] __device_attach+0x105/0x2d0 drivers/base/dd.c:1008 [<ffffffff82711d36>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:487 [<ffffffff8270e242>] device_add+0x642/0xdc0 drivers/base/core.c:3517 [<ffffffff82d14d5f>] usb_set_configuration+0x8ef/0xb80 drivers/usb/core/message.c:2170 [<ffffffff82d2576c>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238 [<ffffffff82d16ffc>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293 [<ffffffff82712f0d>] call_driver_probe drivers/base/dd.c:560 [inline] [<ffffffff82712f0d>] really_probe+0x12d/0x390 drivers/base/dd.c:639 [<ffffffff8271322f>] __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 syzkaller@googlegroups.com Tested-by: Dongliang Mu dzm91@hust.edu.cn Signed-off-by: Dongliang Mu dzm91@hust.edu.cn Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/video/fbdev/smscufx.c | 46 ++++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 15 deletions(-)
--- a/drivers/video/fbdev/smscufx.c +++ b/drivers/video/fbdev/smscufx.c @@ -1621,7 +1621,7 @@ static int ufx_usb_probe(struct usb_inte struct usb_device *usbdev; struct ufx_data *dev; struct fb_info *info; - int retval; + int retval = -ENOMEM; u32 id_rev, fpga_rev;
/* usb initialization */ @@ -1653,15 +1653,17 @@ static int ufx_usb_probe(struct usb_inte
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; @@ -1704,22 +1706,34 @@ static int ufx_usb_probe(struct usb_inte 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, @@ -1727,21 +1741,23 @@ static int ufx_usb_probe(struct usb_inte
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)