diff options
| author | Vamsi Krishna Samavedam <vskrishn@codeaurora.org> | 2020-11-30 23:34:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-11 15:25:00 +0300 |
| commit | 974c9391d4a5a55a9d7a440e10df768385558750 (patch) | |
| tree | fb783cf633b6beaf4f04483d6b2049637d132a1d /drivers/usb/gadget/function/f_fs.c | |
| parent | cbb8de543fc520c10a1331a3cf9aca038c0207e8 (diff) | |
| download | linux-974c9391d4a5a55a9d7a440e10df768385558750.tar.xz | |
usb: gadget: f_fs: Use local copy of descriptors for userspace copy
commit a4b98a7512f18534ce33a7e98e49115af59ffa00 upstream.
The function may be unbound causing the ffs_ep and its descriptors
to be freed while userspace is in the middle of an ioctl requesting
the same descriptors. Avoid dangling pointer reference by first
making a local copy of desctiptors before releasing the spinlock.
Fixes: c559a3534109 ("usb: gadget: f_fs: add ioctl returning ep descriptor")
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Vamsi Krishna Samavedam <vskrishn@codeaurora.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201130203453.28154-1-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget/function/f_fs.c')
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 11a501d0664c..bb2edfc77627 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1243,7 +1243,7 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, case FUNCTIONFS_ENDPOINT_DESC: { int desc_idx; - struct usb_endpoint_descriptor *desc; + struct usb_endpoint_descriptor desc1, *desc; switch (epfile->ffs->gadget->speed) { case USB_SPEED_SUPER: @@ -1255,10 +1255,12 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, default: desc_idx = 0; } + desc = epfile->ep->descs[desc_idx]; + memcpy(&desc1, desc, desc->bLength); spin_unlock_irq(&epfile->ffs->eps_lock); - ret = copy_to_user((void __user *)value, desc, desc->bLength); + ret = copy_to_user((void __user *)value, &desc1, desc1.bLength); if (ret) ret = -EFAULT; return ret; |