On Wed, Sep 15, 2021 at 05:41:22AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 926de8c4326c Merge tag 'acpi-5.15-rc1-3' of git://git.kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11fd67ed300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=37df9ef5660a8387 > dashboard link: https://syzkaller.appspot.com/bug?extid=dc3dfba010d7671e05f5 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+dc3dfba010d7671e05f5@xxxxxxxxxxxxxxxxxxxxxxxxx #syz dup: KASAN: use-after-free Write in addr_resolve (2) Frankly, I still can't figure out how this is happening RDMA_USER_CM_CMD_RESOLVE_IP triggers a background work and RDMA_USER_CM_CMD_DESTROY_ID triggers destruction of the memory the work touches. rdma_addr_cancel() is supposed to ensure that the work isn't and won't run. So to hit this we have to either not call rdma_addr_cancel() when it is need, or rdma_addr_cancel() has to be broken and continue to allow the work. I could find nothing along either path, though rdma_addr_cancel() relies on some complicated properties of the workqueues I'm not entirely positive about. Jason
