lkml.org 
[lkml]   [2018]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: KASAN: slab-out-of-bounds Read in process_preds
    On Fri, Apr 27, 2018 at 7:30 AM, syzbot
    <syzbot+e47d942a98e75b4bd03e@syzkaller.appspotmail.com> wrote:
    > Hello,
    >
    > syzbot hit the following crash on bpf-next commit
    > af487c5777709d4b7f874fe1a33f9289d51b9adc (Wed Apr 25 07:56:11 2018 +0000)
    > Merge branch 'bpf-optimize-neg-sums'
    > syzbot dashboard link:
    > https://syzkaller.appspot.com/bug?extid=e47d942a98e75b4bd03e
    >
    > Unfortunately, I don't have any reproducer for this crash yet.
    > Raw console output:
    > https://syzkaller.appspot.com/x/log.txt?id=5744539889303552
    > Kernel config:
    > https://syzkaller.appspot.com/x/.config?id=-2918904850634584293
    > compiler: gcc (GCC) 8.0.1 20180413 (experimental)
    >
    > IMPORTANT: if you fix the bug, please add the following tag to the commit:
    > Reported-by: syzbot+e47d942a98e75b4bd03e@syzkaller.appspotmail.com
    > It will help syzbot understand when the bug is fixed. See footer for
    > details.
    > If you forward the report, please keep this part and the footer.

    #syz dup: KASAN: use-after-free Read in process_preds

    > ==================================================================
    > BUG: KASAN: slab-out-of-bounds in predicate_parse
    > kernel/trace/trace_events_filter.c:562 [inline]
    > BUG: KASAN: slab-out-of-bounds in process_preds+0x196f/0x19b0
    > kernel/trace/trace_events_filter.c:1505
    > Read of size 4 at addr ffff8801b2b55ff0 by task syz-executor7/7974
    >
    > CPU: 1 PID: 7974 Comm: syz-executor7 Not tainted 4.17.0-rc1+ #12
    > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
    > Google 01/01/2011
    > 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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
    > predicate_parse kernel/trace/trace_events_filter.c:562 [inline]
    > process_preds+0x196f/0x19b0 kernel/trace/trace_events_filter.c:1505
    > create_filter+0x155/0x270 kernel/trace/trace_events_filter.c:1713
    > ftrace_profile_set_filter+0x130/0x2e0
    > kernel/trace/trace_events_filter.c:2038
    > perf_event_set_filter+0x248/0x1230 kernel/events/core.c:9075
    > _perf_ioctl+0x84c/0x15e0 kernel/events/core.c:5059
    > perf_ioctl+0x59/0x80 kernel/events/core.c:5110
    > vfs_ioctl fs/ioctl.c:46 [inline]
    > file_ioctl fs/ioctl.c:500 [inline]
    > do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684
    > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
    > __do_sys_ioctl fs/ioctl.c:708 [inline]
    > __se_sys_ioctl fs/ioctl.c:706 [inline]
    > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
    > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
    > entry_SYSCALL_64_after_hwframe+0x49/0xbe
    > RIP: 0033:0x455389
    > RSP: 002b:00007f63bbd38c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
    > RAX: ffffffffffffffda RBX: 00007f63bbd396d4 RCX: 0000000000455389
    > RDX: 0000000020000040 RSI: 0000000040082406 RDI: 0000000000000013
    > RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
    > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
    > R13: 000000000000029a R14: 00000000006f6f10 R15: 0000000000000000
    >
    > Allocated by task 6559:
    > 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
    > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
    > kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
    > anon_vma_chain_alloc mm/rmap.c:128 [inline]
    > anon_vma_clone+0x138/0x720 mm/rmap.c:268
    > anon_vma_fork+0xe8/0x950 mm/rmap.c:331
    > dup_mmap kernel/fork.c:468 [inline]
    > dup_mm kernel/fork.c:1235 [inline]
    > copy_mm kernel/fork.c:1289 [inline]
    > copy_process.part.38+0x2f21/0x6e90 kernel/fork.c:1795
    > copy_process kernel/fork.c:1608 [inline]
    > _do_fork+0x291/0x12a0 kernel/fork.c:2089
    > __do_sys_clone kernel/fork.c:2196 [inline]
    > __se_sys_clone kernel/fork.c:2190 [inline]
    > __x64_sys_clone+0xbf/0x150 kernel/fork.c:2190
    > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
    > entry_SYSCALL_64_after_hwframe+0x49/0xbe
    >
    > Freed by task 7294:
    > 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]
    > kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
    > anon_vma_chain_free mm/rmap.c:133 [inline]
    > unlink_anon_vmas+0x3aa/0xa40 mm/rmap.c:400
    > free_pgtables+0x271/0x380 mm/memory.c:641
    > exit_mmap+0x2ca/0x570 mm/mmap.c:3057
    > __mmput kernel/fork.c:962 [inline]
    > mmput+0x251/0x610 kernel/fork.c:983
    > exec_mmap fs/exec.c:1044 [inline]
    > flush_old_exec+0xb94/0x20e0 fs/exec.c:1276
    > load_elf_binary+0xa33/0x5610 fs/binfmt_elf.c:869
    > search_binary_handler+0x17d/0x570 fs/exec.c:1653
    > exec_binprm fs/exec.c:1695 [inline]
    > do_execveat_common.isra.34+0x16ce/0x2590 fs/exec.c:1817
    > do_execve fs/exec.c:1862 [inline]
    > __do_sys_execve fs/exec.c:1943 [inline]
    > __se_sys_execve fs/exec.c:1938 [inline]
    > __x64_sys_execve+0x8d/0xb0 fs/exec.c:1938
    > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
    > entry_SYSCALL_64_after_hwframe+0x49/0xbe
    >
    > The buggy address belongs to the object at ffff8801b2b55f60
    > which belongs to the cache anon_vma_chain of size 64
    > The buggy address is located 80 bytes to the right of
    > 64-byte region [ffff8801b2b55f60, ffff8801b2b55fa0)
    > The buggy address belongs to the page:
    > page:ffffea0006cad540 count:1 mapcount:0 mapping:ffff8801b2b55000 index:0x0
    > flags: 0x2fffc0000000100(slab)
    > raw: 02fffc0000000100 ffff8801b2b55000 0000000000000000 000000010000002a
    > raw: ffffea0006a72060 ffffea0006f615e0 ffff8801da94a500 0000000000000000
    > page dumped because: kasan: bad access detected
    >
    > Memory state around the buggy address:
    > ffff8801b2b55e80: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc
    > ffff8801b2b55f00: fb fb fb fb fb fb fb fb fc fc fc fc fb fb fb fb
    >>
    >> ffff8801b2b55f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
    >
    > ^
    > ffff8801b2b56000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    > ffff8801b2b56080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    > ==================================================================
    >
    >
    > ---
    > This bug is generated by a dumb bot. It may contain errors.
    > See https://goo.gl/tpsmEJ for details.
    > Direct all questions to syzkaller@googlegroups.com.
    >
    > syzbot will keep track of this bug report.
    > If you forgot to add the Reported-by tag, once the fix for this bug is
    > merged
    > into any tree, please reply to this email with:
    > #syz fix: exact-commit-title
    > To mark this as a duplicate of another syzbot report, please reply with:
    > #syz dup: exact-subject-of-another-report
    > If it's a one-off invalid bug report, please reply with:
    > #syz invalid
    > Note: if the crash happens again, it will cause creation of a new bug
    > report.
    > Note: all commands must start from beginning of the line in the email body.
    >
    > --
    > You received this message because you are subscribed to the Google Groups
    > "syzkaller-bugs" group.
    > To unsubscribe from this group and stop receiving emails from it, send an
    > email to syzkaller-bugs+unsubscribe@googlegroups.com.
    > To view this discussion on the web visit
    > https://groups.google.com/d/msgid/syzkaller-bugs/000000000000c471f4056acdcb9a%40google.com.
    > For more options, visit https://groups.google.com/d/optout.

    \
     
     \ /
      Last update: 2018-04-27 17:21    [W:4.004 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site