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| author | Fei Yang <fei.yang@intel.com> | 2019-06-12 15:13:26 -0700 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-06-18 11:58:28 +0300 |
| commit | 4833a94eb383f5b22775077ff92ddaae90440921 (patch) | |
| tree | 80eec2a8951c6983fae7c04dbb5518423f3a2f2d /drivers/usb/gadget | |
| parent | c846b03ff767149d75d4d8dca6d3d4945a21074a (diff) | |
| download | linux-4833a94eb383f5b22775077ff92ddaae90440921.tar.bz2 | |
usb: gadget: f_fs: data_len used before properly set
The following line of code in function ffs_epfile_io is trying to set
flag io_data->use_sg in case buffer required is larger than one page.
io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE;
However at this point of time the variable data_len has not been set
to the proper buffer size yet. The consequence is that io_data->use_sg
is always set regardless what buffer size really is, because the condition
(data_len > PAGE_SIZE) is effectively an unsigned comparison between
-EINVAL and PAGE_SIZE which would always result in TRUE.
Fixes: 772a7a724f69 ("usb: gadget: f_fs: Allow scatter-gather buffers")
Signed-off-by: Fei Yang <fei.yang@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 47be961f1bf3..c7ed90084d1a 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -997,7 +997,6 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) * earlier */ gadget = epfile->ffs->gadget; - io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; spin_lock_irq(&epfile->ffs->eps_lock); /* In the meantime, endpoint got disabled or changed. */ @@ -1012,6 +1011,8 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) */ if (io_data->read) data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); + + io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; spin_unlock_irq(&epfile->ffs->eps_lock); data = ffs_alloc_buffer(io_data, data_len); |