Jason Gunthorpe 于2021年4月13日周二 下午9:45写道: > > On Tue, Apr 13, 2021 at 09:42:43PM +0800, Hao Sun wrote: > > Jason Gunthorpe 于2021年4月13日周二 下午9:34写道: > > > > > > On Tue, Apr 13, 2021 at 11:36:41AM +0800, Hao Sun wrote: > > > > Hi > > > > > > > > When using Healer(https://github.com/SunHao-0/healer/tree/dev) to fuzz > > > > the Linux kernel, I found two use-after-free bugs which have been > > > > reported a long time ago by Syzbot. > > > > Although the corresponding patches have been merged into upstream, > > > > these two bugs can still be triggered easily. > > > > The original information about Syzbot report can be found here: > > > > https://syzkaller.appspot.com/bug?id=8dc0bcd9dd6ec915ba10b3354740eb420884acaa > > > > https://syzkaller.appspot.com/bug?id=95f89b8fb9fdc42e28ad586e657fea074e4e719b > > > > > > Then why hasn't syzbot seen this in a year's time? Seems strange > > > > > > > Seems strange to me too, but the fact is that the reproduction program > > in attachment can trigger these two bugs quickly. > > Do you have this in the C format? > Just tried to use syz-prog2c to convert the repro-prog to C format. The repro program of rdma_listen was successfully reproduced (uploaded in attachment), the other one failed. it looks like syz-prog2c may not be able to do the equivalent conversion. You can use syz-execprog to execute the reprogram directly, this method can reproduce both crashes, I have tried it. For reproduction prog of cma_cancel_operation, using syz-execprog can run this reproduction program directly: ./syz-execprog -threaded -repeat 0 -procs 2 -slowdown 1 -enable tun -enable netdev -enable resetnet -enable cgroups -enable binfmt-misc -enable close_fds -enable devlinkpci -enable usb -enable vhci -enable wifi -enable ieee802154 -enable sysctl repro.prog