From: Udipto Goswami ugoswami@codeaurora.org
commit 1c2e54fbf1da5e5445a0ab132c862b02ccd8d230 upstream.
For userspace functions using OS Descriptors, if a function also supplies Extended Property descriptors currently the counts and lengths stored in the ms_os_descs_ext_prop_{count,name_len,data_len} variables are not getting reset to 0 during an unbind or when the epfiles are closed. If the same function is re-bound and the descriptors are re-written, this results in those count/length variables to monotonically increase causing the VLA allocation in _ffs_func_bind() to grow larger and larger at each bind/unbind cycle and eventually fail to allocate.
Fix this by clearing the ms_os_descs_ext_prop count & lengths to 0 in ffs_data_reset().
Fixes: f0175ab51993 ("usb: gadget: f_fs: OS descriptors support") Cc: stable@vger.kernel.org Signed-off-by: Udipto Goswami ugoswami@codeaurora.org Signed-off-by: Sriharsha Allenki sallenki@codeaurora.org Reviewed-by: Manu Gautam mgautam@codeaurora.org Link: https://lore.kernel.org/r/20200402044521.9312-1-sallenki@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/gadget/function/f_fs.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1511,6 +1511,10 @@ static void ffs_data_reset(struct ffs_da ffs->state = FFS_READ_DESCRIPTORS; ffs->setup_state = FFS_NO_SETUP; ffs->flags = 0; + + ffs->ms_os_descs_ext_prop_count = 0; + ffs->ms_os_descs_ext_prop_name_len = 0; + ffs->ms_os_descs_ext_prop_data_len = 0; }