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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id x9sm6106149pfj.96.2020.09.12.10.52.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Sep 2020 10:52:53 -0700 (PDT) Date: Sat, 12 Sep 2020 10:52:52 -0700 From: Kees Cook To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, syzbot , syzkaller-bugs@googlegroups.com, Andy Lutomirski Subject: Re: WARNING in syscall_exit_to_user_mode Message-ID: <202009121050.0D9CAB95@keescook> References: <00000000000018a47605af074c7d@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000000000018a47605af074c7d@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 11, 2020 at 03:39:19AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: f4d51dff Linux 5.9-rc4 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12a4e7cd900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a9075b36a6ae26c9 > dashboard link: https://syzkaller.appspot.com/bug?extid=7ffc7214b893651d52b8 > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122d7335900000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13cea1a5900000 > > Bisection is inconclusive: the issue happens on the oldest tested release. > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=162247cd900000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=152247cd900000 > console output: https://syzkaller.appspot.com/x/log.txt?x=112247cd900000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7ffc7214b893651d52b8@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > syscall 56 left IRQs disabled This WARN appears reachable. :) I also see on the dashboard these other problems with the new entry code: https://syzkaller.appspot.com/bug?extid=d4336c84ed0099fdbe47 https://syzkaller.appspot.com/bug?extid=c4af95386364bc59b13e I can't tell if any of these have been looked at yet, though. -- Kees Cook