Re: bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work
On Thu, Jun 7, 2018 at 8:12 PM, Luis R. Rodriguez wrote: >> > wrote: >> > > Hello, >> > > >> > > syzbot found the following crash on: >> > > >> > > HEAD commit:69b450789136 Merge branch 'misc-BPF-improvements' >> > > git tree: bpf-next >> > > console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d780 >> > > kernel config: >> > > https://syzkaller.appspot.com/x/.config?x=e4078980b886800c >> > > dashboard link: >> > > https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 >> > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) >> > > >> > > Unfortunately, I don't have any reproducer for this crash yet. >> > > >> > > IMPORTANT: if you fix the bug, please add the following tag to the >> > > commit: >> > > Reported-by: syzbot+2c73319c406f1987d...@syzkaller.appspotmail.com >> > >> > >> > This crash now happens on every other boot of mainline tree. This >> > prevents syzbot testing of new code, and just boots machine with >> > corrupted memory. Were there any recent changes in umh? +Alexei, you >> > seem to touch it last. Could your change cause this? >> >> looking into it. I think I see the issue. Trying to reproduce. > > And this is why a test driver would be useful ;) And also testing everything with KASAN and LOCKDEP ;)
Re: bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work
On Thu, Jun 07, 2018 at 09:07:01AM -0700, Alexei Starovoitov wrote: > On Thu, Jun 07, 2018 at 02:19:16PM +0200, Dmitry Vyukov wrote: > > On Mon, Jun 4, 2018 at 10:21 PM, syzbot > > wrote: > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit:69b450789136 Merge branch 'misc-BPF-improvements' > > > git tree: bpf-next > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d780 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=e4078980b886800c > > > dashboard link: > > > https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 > > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+2c73319c406f1987d...@syzkaller.appspotmail.com > > > > > > This crash now happens on every other boot of mainline tree. This > > prevents syzbot testing of new code, and just boots machine with > > corrupted memory. Were there any recent changes in umh? +Alexei, you > > seem to touch it last. Could your change cause this? > > looking into it. I think I see the issue. Trying to reproduce. And this is why a test driver would be useful ;) Luis
Re: bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work
On Thu, Jun 07, 2018 at 02:19:16PM +0200, Dmitry Vyukov wrote: > On Mon, Jun 4, 2018 at 10:21 PM, syzbot > wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit:69b450789136 Merge branch 'misc-BPF-improvements' > > git tree: bpf-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d780 > > kernel config: https://syzkaller.appspot.com/x/.config?x=e4078980b886800c > > dashboard link: https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+2c73319c406f1987d...@syzkaller.appspotmail.com > > > This crash now happens on every other boot of mainline tree. This > prevents syzbot testing of new code, and just boots machine with > corrupted memory. Were there any recent changes in umh? +Alexei, you > seem to touch it last. Could your change cause this? looking into it. I think I see the issue. Trying to reproduce.
Re: bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work
On Mon, Jun 4, 2018 at 10:21 PM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit:69b450789136 Merge branch 'misc-BPF-improvements' > git tree: bpf-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d780 > kernel config: https://syzkaller.appspot.com/x/.config?x=e4078980b886800c > dashboard link: https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+2c73319c406f1987d...@syzkaller.appspotmail.com This crash now happens on every other boot of mainline tree. This prevents syzbot testing of new code, and just boots machine with corrupted memory. Were there any recent changes in umh? +Alexei, you seem to touch it last. Could your change cause this? > kworker/u4:1 (36) used greatest stack depth: 23056 bytes left > cpuidle: using governor menu > ACPI: bus type PCI registered > PCI: Using configuration type 1 for base access > == > BUG: KASAN: use-after-free in call_usermodehelper_exec_work+0x2d3/0x310 > kernel/umh.c:195 > Write of size 4 at addr 8801d9202370 by task kworker/u4:2/50 > > CPU: 0 PID: 50 Comm: kworker/u4:2 Not tainted 4.17.0-rc6+ #32 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: events_unbound call_usermodehelper_exec_work > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > print_address_description+0x6c/0x20b mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 > __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437 > call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195 > process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 > worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 > kthread+0x345/0x410 kernel/kthread.c:240 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 > > Allocated by task 1: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 > kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 > kmalloc include/linux/slab.h:512 [inline] > kzalloc include/linux/slab.h:701 [inline] > call_usermodehelper_setup+0xe8/0x400 kernel/umh.c:382 > kobject_uevent_env+0xb21/0x1110 lib/kobject_uevent.c:608 > kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:636 > kernel_add_sysfs_param kernel/params.c:798 [inline] > param_sysfs_builtin kernel/params.c:833 [inline] > param_sysfs_init+0x3f9/0x486 kernel/params.c:954 > do_one_initcall+0x127/0x913 init/main.c:884 > do_initcall_level init/main.c:952 [inline] > do_initcalls init/main.c:960 [inline] > do_basic_setup init/main.c:978 [inline] > kernel_init_freeable+0x49b/0x58e init/main.c:1135 > kernel_init+0x11/0x1b3 init/main.c:1061 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 > > Freed by task 208: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xd9/0x260 mm/slab.c:3813 > call_usermodehelper_freeinfo kernel/umh.c:45 [inline] > umh_complete+0x7b/0x90 kernel/umh.c:59 > call_usermodehelper_exec_async+0x6e8/0x9e0 kernel/umh.c:116 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 > > The buggy address belongs to the object at 8801d9202300 > which belongs to the cache kmalloc-192 of size 192 > The buggy address is located 112 bytes inside of > 192-byte region [8801d9202300, 8801d92023c0) > The buggy address belongs to the page: > page:ea0007648080 count:1 mapcount:0 mapping:8801d9202000 index:0x0 > flags: 0x2fffc000100(slab) > raw: 02fffc000100 8801d9202000 00010010 > raw: ea0007647f60 8801da801148 8801da800040 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > 8801d9202200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > 8801d9202280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ^ > 8801d9202380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > 8801d9202400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > == > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to
bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work
Hello, syzbot found the following crash on: HEAD commit:69b450789136 Merge branch 'misc-BPF-improvements' git tree: bpf-next console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d780 kernel config: https://syzkaller.appspot.com/x/.config?x=e4078980b886800c dashboard link: https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+2c73319c406f1987d...@syzkaller.appspotmail.com kworker/u4:1 (36) used greatest stack depth: 23056 bytes left cpuidle: using governor menu ACPI: bus type PCI registered PCI: Using configuration type 1 for base access == BUG: KASAN: use-after-free in call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195 Write of size 4 at addr 8801d9202370 by task kworker/u4:2/50 CPU: 0 PID: 50 Comm: kworker/u4:2 Not tainted 4.17.0-rc6+ #32 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound call_usermodehelper_exec_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437 call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Allocated by task 1: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:512 [inline] kzalloc include/linux/slab.h:701 [inline] call_usermodehelper_setup+0xe8/0x400 kernel/umh.c:382 kobject_uevent_env+0xb21/0x1110 lib/kobject_uevent.c:608 kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:636 kernel_add_sysfs_param kernel/params.c:798 [inline] param_sysfs_builtin kernel/params.c:833 [inline] param_sysfs_init+0x3f9/0x486 kernel/params.c:954 do_one_initcall+0x127/0x913 init/main.c:884 do_initcall_level init/main.c:952 [inline] do_initcalls init/main.c:960 [inline] do_basic_setup init/main.c:978 [inline] kernel_init_freeable+0x49b/0x58e init/main.c:1135 kernel_init+0x11/0x1b3 init/main.c:1061 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Freed by task 208: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 call_usermodehelper_freeinfo kernel/umh.c:45 [inline] umh_complete+0x7b/0x90 kernel/umh.c:59 call_usermodehelper_exec_async+0x6e8/0x9e0 kernel/umh.c:116 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at 8801d9202300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 112 bytes inside of 192-byte region [8801d9202300, 8801d92023c0) The buggy address belongs to the page: page:ea0007648080 count:1 mapcount:0 mapping:8801d9202000 index:0x0 flags: 0x2fffc000100(slab) raw: 02fffc000100 8801d9202000 00010010 raw: ea0007647f60 8801da801148 8801da800040 page dumped because: kasan: bad access detected Memory state around the buggy address: 8801d9202200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 8801d9202280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 8801d9202300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ 8801d9202380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc 8801d9202400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb == --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkal...@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.
