Messages in this thread | | | From | Dmitry Vyukov <> | Date | Mon, 9 Mar 2020 09:34:25 +0100 | Subject | Re: general protection fault in syscall_return_slowpath |
| |
On Sun, Mar 8, 2020 at 7:26 PM Thomas Gleixner <tglx@linutronix.de> wrote: > > Andy Lutomirski <luto@kernel.org> writes: > > On Sat, Mar 7, 2020 at 11:45 PM syzbot > > <syzbot+cd66e43794b178bb5cd6@syzkaller.appspotmail.com> wrote: > > $ make -j4 > > tools/syz-env/env.go:14:2: cannot find package > > "github.com/google/syzkaller/pkg/osutil" in any of: > > > > I'm sure that if I actually understood Go's delightful packaging > > system, I could reverse engineer your build system and figure out how > > to make it work. But perhaps you could document the build process? > > Or maybe make 'make' just work? > > > > For kicks, I tried this: > > > > $ mkdir -p src/github.com/google > > $ ln -sr . src/github.com/google/syzkaller > > $ GOPATH=`/bin/pwd` make > > GOOS=linux GOARCH=amd64 go install ./syz-manager > > go install: no install location for directory > > /home/luto/apps/syzkaller/syz-manager outside GOPATH > > > > Are there instructions for just building syzkaller? I don't want to > > install it, I don't want to fuzz my kernel -- I just want to run your > > reproducer. > > https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md > > That's how I build the binaries: > > mkdir foo > export GOPATH=$HOME/foo > > cd foo > go get -u -d github.com/google/syzkaller/... > cd src/github.com/google/syzkaller > make > cp bin/linux_amd64/syz-execprog bin/linux_amd64/syz-executor $GOPATH > > Of course you can build it somewhere and scp the executables to a test box. > > And then to run it > > cd $GOPATH > wget -O repro.syz https://syzkaller.appspot.com/x/repro.syz?x=12a42329e00000 > ./syz-execprog -procs 6 -repeat 0 -collide -disable none repro.syz > > The command line options are a bit tedious as you have to look them up > in the comment in repro.syz. > > A scripts which converts that comment into command line options or > syz-execprog simply taking it from repro.syz would indeed be handy. > > A kernel with the config provided in the report and running that > reproducer is still not reproducing with a runtime of 8hrs+ :( > > Thanks, > > tglx
I see the repro opens /dev/fb0, so this may be related to the exact type of framebuffer on the machine. That's what Jann tried to figure out.
There is a plenty of open bugs on dashboard related to fb/tty, just doing a quick grep based on titles:
https://syzkaller.appspot.com/upstream BUG: unable to handle kernel paging request in drm_fb_helper_dirty_work 7 4d20h 90d BUG: unable to handle kernel paging request in vga16fb_imageblit 1 74d 73d divide error in fbcon_switch C cause 141 3d15h 96d general protection fault in fbcon_cursor C cause 12 13h48m 87d general protection fault in fbcon_fb_blanked 3 88d 90d general protection fault in fbcon_invert_region 1 49d 48d general protection fault in fbcon_modechanged 3 89d 90d INFO: task hung in do_fb_ioctl 6 36d 57d INFO: task hung in fb_compat_ioctl 1 87d 87d INFO: task hung in fb_open C cause 171 1h06m 96d INFO: task hung in fb_release C cause 23 2d12h 77d INFO: task hung in release_tty 3 6d16h 62d INFO: task hung in tty_ldisc_hangup C cause 15 17d 92d INFO: trying to register non-static key in hci_uart_tty_receive (2) 1 103d 99d KASAN: global-out-of-bounds Read in fbcon_get_font C cause 19 7d06h 90d KASAN: global-out-of-bounds Read in fb_pad_aligned_buffer C cause 5 4d22h 92d KASAN: global-out-of-bounds Read in vga16fb_imageblit C cause 225 1d11h 96d KASAN: slab-out-of-bounds Read in fbcon_get_font C cause 42 5d04h 96d KASAN: slab-out-of-bounds Read in fb_pad_aligned_buffer 4 9d00h 48d KASAN: slab-out-of-bounds Write in fbcon_scroll 1 75d 73d KASAN: use-after-free Read in fbcon_cursor syz cause 3 41d 84d KASAN: use-after-free Read in fb_mode_is_equal syz cause 70 5h49m 92d KASAN: use-after-free Read in tty_open C cause 7 42d 96d KASAN: use-after-free Write in release_tty C cause 544 4h01m 96d KASAN: vmalloc-out-of-bounds Read in drm_fb_helper_dirty_work 1 80d 80d KASAN: vmalloc-out-of-bounds Write in drm_fb_helper_dirty_work 2 64d 76d KCSAN: data-race in echo_char / n_tty_receive_buf_common 11 21d 125d KMSAN: kernel-infoleak in tty_compat_ioctl C 81 2h17m 14d memory leak in tty_init_dev C 3 121d 192d possible deadlock in n_tty_receive_buf_common C cause 585 1h18m 23d possible deadlock in tty_port_close_start C cause 4 9d18h 25d WARNING in dlfb_submit_urb/usb_submit_urb C 190 8d23h 251d
So if you don't see something obvious here, it may be not worth spending more time until these, more obvious ones are fixed. This may be a previous silent memory corruption that wasn't caught by KASAN.
| |