On Mon, Jan 10, 2022 at 09:23:22PM +0800, Ziyang Xuan wrote: > From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > [ commit bf74aa86e111aa3b2fbb25db37e3a3fab71b5b68 upstream ] > > Stop tx/rx cycle rely on the active state of tasklet and hrtimer > sequentially in bcm_remove_op(), the op object will be freed if they > are all unactive. Assume the hrtimer timeout is short, the hrtimer > cb has been excuted after tasklet conditional judgment which must be > false after last round tasklet_kill() and before condition > hrtimer_active(), it is false when execute to hrtimer_active(). Bug > is triggerd, because the stopping action is end and the op object > will be freed, but the tasklet is scheduled. The resources of the op > object will occur UAF bug. That is not the changelog text of this commit. Why modify it? > > ---------------------------------------------------------------------- > > This patch switches the timer to HRTIMER_MODE_SOFT, which executed the > timer callback in softirq context and removes the hrtimer_tasklet. > > Reported-by: syzbot+652023d5376450cc8516@xxxxxxxxxxxxxxxxxxxxxxxxx > Cc: stable@xxxxxxxxxxxxxxx # 4.19 > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx> > Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> > Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> > Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx> > --- > net/can/bcm.c | 156 +++++++++++++++++--------------------------------- > 1 file changed, 52 insertions(+), 104 deletions(-) What stable kernel tree(s) are you wanting this backported to? thanks, greg k-h
