From: Udipto Goswami ugoswami@codeaurora.org

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 --- Changes from v1: - Removed Change-ID

drivers/usb/gadget/function/f_fs.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c81023b195c3..10f01f974f67 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1813,6 +1813,10 @@ static void ffs_data_reset(struct ffs_data *ffs) 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; }