On Sun, Mar 24, 2024 at 5:07 PM Alexei Starovoitov
<alexei.starovoi...@gmail.com> wrote:
>
> Hi Andrii,
>
> syzbot found UAF in raw_tp cookie series in bpf-next.
> Reverting the whole merge
> 2e244a72cd48 ("Merge branch 'bpf-raw-tracepoint-support-for-bpf-cookie'")
>
> fixes the issue.
>
> Pls take a look.
> See C reproducer below. It splats consistently with CONFIG_KASAN=y
>
> Thanks.Will do, traveling today, so will be offline for a bit, but will check first thing afterwards. > > On Sun, Mar 24, 2024 at 4:28 PM syzbot > <syzbot+981935d9485a560bf...@syzkaller.appspotmail.com> wrote: > > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 520fad2e3206 selftests/bpf: scale benchmark counting by us.. > > git tree: bpf-next > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=105af946180000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 > > dashboard link: https://syzkaller.appspot.com/bug?extid=981935d9485a560bfbcb > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for > > Debian) 2.40 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=114f17a5180000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162bb7a5180000 > > > > Downloadable assets: > > disk image: > > https://storage.googleapis.com/syzbot-assets/4eef3506c5ce/disk-520fad2e.raw.xz > > vmlinux: > > https://storage.googleapis.com/syzbot-assets/24d60ebe76cc/vmlinux-520fad2e.xz > > kernel image: > > https://storage.googleapis.com/syzbot-assets/8f883e706550/bzImage-520fad2e.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+981935d9485a560bf...@syzkaller.appspotmail.com > > > > ================================================================== > > BUG: KASAN: slab-use-after-free in __bpf_trace_run > > kernel/trace/bpf_trace.c:2376 [inline] > > BUG: KASAN: slab-use-after-free in bpf_trace_run1+0xcb/0x510 > > kernel/trace/bpf_trace.c:2430 > > Read of size 8 at addr ffff8880290d9918 by task migration/0/19 > > > > CPU: 0 PID: 19 Comm: migration/0 Not tainted > > 6.8.0-syzkaller-05233-g520fad2e3206 #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 02/29/2024 > > Stopper: 0x0 <- 0x0 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 > > print_address_description mm/kasan/report.c:377 [inline] > > print_report+0x169/0x550 mm/kasan/report.c:488 > > kasan_report+0x143/0x180 mm/kasan/report.c:601 > > __bpf_trace_run kernel/trace/bpf_trace.c:2376 [inline] > > bpf_trace_run1+0xcb/0x510 kernel/trace/bpf_trace.c:2430 > > __traceiter_rcu_utilization+0x74/0xb0 include/trace/events/rcu.h:27 > > trace_rcu_utilization+0x194/0x1c0 include/trace/events/rcu.h:27 > > rcu_note_context_switch+0xc7c/0xff0 kernel/rcu/tree_plugin.h:360 > > __schedule+0x345/0x4a20 kernel/sched/core.c:6635 > > __schedule_loop kernel/sched/core.c:6813 [inline] > > schedule+0x14b/0x320 kernel/sched/core.c:6828 > > smpboot_thread_fn+0x61e/0xa30 kernel/smpboot.c:160 > > kthread+0x2f0/0x390 kernel/kthread.c:388 > > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 > > </TASK> > > > > Allocated by task 5075: > > kasan_save_stack mm/kasan/common.c:47 [inline] > > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > > poison_kmalloc_redzone mm/kasan/common.c:370 [inline] > > __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 > > kasan_kmalloc include/linux/kasan.h:211 [inline] > > kmalloc_trace+0x1d9/0x360 mm/slub.c:4012 > > kmalloc include/linux/slab.h:590 [inline] > > kzalloc include/linux/slab.h:711 [inline] > > bpf_raw_tp_link_attach+0x2a0/0x6e0 kernel/bpf/syscall.c:3816 > > bpf_raw_tracepoint_open+0x1c2/0x240 kernel/bpf/syscall.c:3863 > > __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5673 > > __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] > > __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] > > __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 > > do_syscall_64+0xfb/0x240 > > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > > > Freed by task 5075: > > kasan_save_stack mm/kasan/common.c:47 [inline] > > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > > kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:589 > > poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 > > __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 > > kasan_slab_free include/linux/kasan.h:184 [inline] > > slab_free_hook mm/slub.c:2121 [inline] > > slab_free mm/slub.c:4299 [inline] > > kfree+0x14a/0x380 mm/slub.c:4409 > > bpf_link_release+0x3b/0x50 kernel/bpf/syscall.c:3071 > > __fput+0x429/0x8a0 fs/file_table.c:423 > > task_work_run+0x24f/0x310 kernel/task_work.c:180 > > exit_task_work include/linux/task_work.h:38 [inline] > > do_exit+0xa1b/0x27e0 kernel/exit.c:878 > > do_group_exit+0x207/0x2c0 kernel/exit.c:1027 > > __do_sys_exit_group kernel/exit.c:1038 [inline] > > __se_sys_exit_group kernel/exit.c:1036 [inline] > > __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 > > do_syscall_64+0xfb/0x240 > > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > > > The buggy address belongs to the object at ffff8880290d9900 > > which belongs to the cache kmalloc-128 of size 128 > > The buggy address is located 24 bytes inside of > > freed 128-byte region [ffff8880290d9900, ffff8880290d9980) > > > > The buggy address belongs to the physical page: > > page:ffffea0000a43640 refcount:1 mapcount:0 mapping:0000000000000000 > > index:0x0 pfn:0x290d9 > > anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) > > page_type: 0xffffffff() > > raw: 00fff00000000800 ffff888014c418c0 0000000000000000 0000000000000001 > > raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 > > page dumped because: kasan: bad access detected > > page_owner tracks the page as allocated > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 4527, tgid 4527 > > (udevd), ts 43150902736, free_ts 43094996342 > > set_page_owner include/linux/page_owner.h:31 [inline] > > post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 > > prep_new_page mm/page_alloc.c:1540 [inline] > > get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 > > __alloc_pages+0x256/0x680 mm/page_alloc.c:4569 > > __alloc_pages_node include/linux/gfp.h:238 [inline] > > alloc_pages_node include/linux/gfp.h:261 [inline] > > alloc_slab_page+0x5f/0x160 mm/slub.c:2190 > > allocate_slab mm/slub.c:2354 [inline] > > new_slab+0x84/0x2f0 mm/slub.c:2407 > > ___slab_alloc+0xd1b/0x13e0 mm/slub.c:3540 > > __slab_alloc mm/slub.c:3625 [inline] > > __slab_alloc_node mm/slub.c:3678 [inline] > > slab_alloc_node mm/slub.c:3850 [inline] > > kmalloc_trace+0x267/0x360 mm/slub.c:4007 > > kmalloc include/linux/slab.h:590 [inline] > > kzalloc include/linux/slab.h:711 [inline] > > kernfs_get_open_node fs/kernfs/file.c:523 [inline] > > kernfs_fop_open+0x803/0xcd0 fs/kernfs/file.c:691 > > do_dentry_open+0x907/0x15a0 fs/open.c:956 > > do_open fs/namei.c:3643 [inline] > > path_openat+0x2860/0x3240 fs/namei.c:3800 > > do_filp_open+0x235/0x490 fs/namei.c:3827 > > do_sys_openat2+0x13e/0x1d0 fs/open.c:1407 > > do_sys_open fs/open.c:1422 [inline] > > __do_sys_openat fs/open.c:1438 [inline] > > __se_sys_openat fs/open.c:1433 [inline] > > __x64_sys_openat+0x247/0x2a0 fs/open.c:1433 > > do_syscall_64+0xfb/0x240 > > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > page last free pid 4526 tgid 4526 stack trace: > > reset_page_owner include/linux/page_owner.h:24 [inline] > > free_pages_prepare mm/page_alloc.c:1140 [inline] > > free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346 > > free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 > > rcu_do_batch kernel/rcu/tree.c:2196 [inline] > > rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 > > __do_softirq+0x2bc/0x943 kernel/softirq.c:554 > > > > Memory state around the buggy address: > > ffff8880290d9800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8880290d9880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > >ffff8880290d9900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff8880290d9980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8880290d9a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > > > > --- > > This report 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 issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > > > If the report is already addressed, let syzbot know by replying with: > > #syz fix: exact-commit-title > > > > If you want syzbot to run the reproducer, reply with: > > #syz test: git://repo/address.git branch-or-commit-hash > > If you attach or paste a git patch, syzbot will apply it before testing. > > > > If you want to overwrite report's subsystems, reply with: > > #syz set subsystems: new-subsystem > > (See the list of subsystem names on the web dashboard) > > > > If the report is a duplicate of another one, reply with: > > #syz dup: exact-subject-of-another-report > > > > If you want to undo deduplication, reply with: > > #syz undup
