On Thu, Dec 23, 2021 at 02:26:26PM +0900, Nobuhiro Iwamatsu wrote: > From: Eddie Hung <eddie.hung@xxxxxxxxxxxx> > > commit 64e6bbfff52db4bf6785fab9cffab850b2de6870 upstream. > > There is a use-after-free issue, if access udc_name > in function gadget_dev_desc_UDC_store after another context > free udc_name in function unregister_gadget. > > Context 1: > gadget_dev_desc_UDC_store()->unregister_gadget()-> > free udc_name->set udc_name to NULL > > Context 2: > gadget_dev_desc_UDC_show()-> access udc_name > > Call trace: > dump_backtrace+0x0/0x340 > show_stack+0x14/0x1c > dump_stack+0xe4/0x134 > print_address_description+0x78/0x478 > __kasan_report+0x270/0x2ec > kasan_report+0x10/0x18 > __asan_report_load1_noabort+0x18/0x20 > string+0xf4/0x138 > vsnprintf+0x428/0x14d0 > sprintf+0xe4/0x12c > gadget_dev_desc_UDC_show+0x54/0x64 > configfs_read_file+0x210/0x3a0 > __vfs_read+0xf0/0x49c > vfs_read+0x130/0x2b4 > SyS_read+0x114/0x208 > el0_svc_naked+0x34/0x38 > > Add mutex_lock to protect this kind of scenario. > > Signed-off-by: Eddie Hung <eddie.hung@xxxxxxxxxxxx> > Signed-off-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx> > Reviewed-by: Peter Chen <peter.chen@xxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Link: https://lore.kernel.org/r/1609239215-21819-1-git-send-email-macpaul.lin@xxxxxxxxxxxx > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > [Reference: CVE-2021-39648] > [iwamatsu: struct usb_gadget_driver does not have udc_name variable. > Change struct gadget_info's udc_name.] > Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@xxxxxxxxxxxxx> > --- > drivers/usb/gadget/configfs.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) Now queued up, thanks. greg k-h
