On Sun, Mar 7, 2021 at 11:09 AM Hillf Danton <hdanton@xxxxxxxx> wrote: > > On Sun, 7 Mar 2021 08:46:19 +0100 Dmitry Vyukov wrote: > > On Sun, Mar 7, 2021 at 3:15 AM Hillf Danton <hdanton@xxxxxxxx> wrote: > > > > > > Dmitry can you shed some light on the tricks to config kasan to print > > > Call Trace as the reports with the leading [syzbot] on the subject line do? > > > > +kasan-dev > > > > Hi Hillf, > > > > KASAN prints stack traces always unconditionally. There is nothing you > > need to do at all. > > Got it, thanks. > > > Do you have any reports w/o stack traces? > > No, but I saw different formats in Call Trace prints. > > Below from [1] is the instance without file name and line number printed, > while both info help spot the cause of the reported issue. KASAN always prints stack traces w/o file:line info, like any other kernel bug detection facility. Kernel itself never symbolizes reports. In case of syzkaller, syzkaller will symbolize reports and add file:line info. The main config it requires is CONFIG_DEBUG_INFO. You may see syzkaller kernel configuration guide here: https://github.com/google/syzkaller/blob/master/docs/linux/kernel_configs.md Or fragments that are actually used to generate syzbot configs in this dir (the guide above may be out-of-date): https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/base.yml https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/debug.yml https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/kasan.yml Or a complete syzbot config here: https://github.com/google/syzkaller/blob/master/dashboard/config/linux/upstream-apparmor-kasan.config > >>>>>>>>>>>>>>>>>>>>>>>>> > > I was running syzkaller and I found the following issue : > > Head Commit : b1313fe517ca3703119dcc99ef3bbf75ab42bcfb ( v5.10.4 ) > Git Tree : stable > Console Output : > [ 242.769080] INFO: task repro:2639 blocked for more than 120 seconds. > [ 242.769096] Not tainted 5.10.4 #8 > [ 242.769103] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > disables this message. > [ 242.769112] task:repro state:D stack: 0 pid: 2639 > ppid: 2638 flags:0x00000004 > [ 242.769126] Call Trace: > [ 242.769148] __schedule+0x28d/0x7e0 > [ 242.769162] ? __percpu_counter_sum+0x75/0x90 > [ 242.769175] schedule+0x4f/0xc0 > [ 242.769187] __io_uring_task_cancel+0xad/0xf0 > [ 242.769198] ? wait_woken+0x80/0x80 > [ 242.769210] bprm_execve+0x67/0x8a0 > [ 242.769223] do_execveat_common+0x1d2/0x220 > [ 242.769235] __x64_sys_execveat+0x5d/0x70 > [ 242.769249] do_syscall_64+0x38/0x90 > [ 242.769260] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > [1] https://lore.kernel.org/lkml/CAGyP=7cFM6BJE7X2PN9YUptQgt5uQYwM4aVmOiVayQPJg1pqaA@xxxxxxxxxxxxxx/
