From: Udipto Goswami <ugoswami@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Udipto Goswami <ugoswami@xxxxxxxxxxxxxx>
Signed-off-by: Sriharsha Allenki <sallenki@xxxxxxxxxxxxxx>
Reviewed-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200402044521.9312-1-sallenki@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -1727,6 +1727,10 @@ 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;
}
