On 22-09-02 15:25:10, Greg Kroah-Hartman wrote: > On Fri, Sep 02, 2022 at 04:13:31PM +0300, Abel Vesa wrote: > > Currently, there is a race window between the point when the mutex is > > unlocked in fastrpc_map_lookup and the reference count increasing > > (fastrpc_map_get) in fastrpc_map_find, which can also lead to > > use-after-free. > > > > So lets merge fastrpc_map_find into fastrpc_map_lookup which allows us > > to both protect the maps list by also taking the &fl->lock spinlock and > > the reference count, since the spinlock will be released only after. > > Add take_ref argument to make this suitable for all callers. > > > > Co-developed-by: Ola Jeppsson <ola@xxxxxxxx> > > Signed-off-by: Ola Jeppsson <ola@xxxxxxxx> > > Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx> > > --- > > drivers/misc/fastrpc.c | 41 +++++++++++++++++++++-------------------- > > 1 file changed, 21 insertions(+), 20 deletions(-) > > What commit does this fix? Should it go to stable trees? Will specify in the next version. > > Try splitting this series up into 2, one for 6.0-final with bugfixes to > resolve issues found, and the next one on top of that for new features. Fair point. Will do in the next version. > > thanks, > > greg k-h
