Is there any comment for this issue? (reference: https://www.spinics.net/lists/kernel/msg4731408.html) 2023년 3월 23일 (목) 오전 10:37, Sangsup Lee <k1rh4.lee@xxxxxxxxx>님이 작성: > > From: Sangsup lee <k1rh4.lee@xxxxxxxxx> > > This patch adds mutex_lock for fixing an Use-after-free bug. > fastrpc_req_munmap_impl can be called concurrently in multi-threded environments. > The buf which is allocated by list_for_each_safe can be used after another thread frees it. > > Signed-off-by: Sangsup lee <k1rh4.lee@xxxxxxxxx> > --- > V1 -> V2: moving the locking to ioctl. > > drivers/misc/fastrpc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index 93ebd174d848..aa1cf0e9f4ed 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -1901,7 +1901,9 @@ static long fastrpc_device_ioctl(struct file *file, unsigned int cmd, > err = fastrpc_req_mmap(fl, argp); > break; > case FASTRPC_IOCTL_MUNMAP: > + mutex_lock(&fl->mutex); > err = fastrpc_req_munmap(fl, argp); > + mutex_unlock(&fl->mutex); > break; > case FASTRPC_IOCTL_MEM_MAP: > err = fastrpc_req_mem_map(fl, argp); > -- > 2.25.1 >
