kauditd_printk_skb: 36 callbacks suppressed audit: type=1326 audit(1507818426.702:481): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=15003 comm="syz-executor2" exe="/root/syz-executor2" sig=31 arch=40000003 syscall=240 compat=1 ip=0xf7fb0c79 code=0xffff0000 ================================================================== BUG: KASAN: use-after-free in arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline] BUG: KASAN: use-after-free in __do_page_fault+0xc03/0xd60 arch/x86/mm/fault.c:1357 Read of size 8 at addr ffff8801d99accf0 by task syz-executor4/14995 CPU: 0 PID: 14995 Comm: syz-executor4 Not tainted 4.14.0-rc4+ #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline] __do_page_fault+0xc03/0xd60 arch/x86/mm/fault.c:1357 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1520 page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1066 RIP: 0023:0x804a11b RSP: 002b:000000000846f8c0 EFLAGS: 00010246 RAX: 0000000020238ff8 RBX: 0000000000000000 RCX: 000000000000fffe RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 15007: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3561 kmem_cache_zalloc include/linux/slab.h:656 [inline] mmap_region+0x7ee/0x15a0 mm/mmap.c:1658 do_mmap+0x6a1/0xd50 mm/mmap.c:1468 do_mmap_pgoff include/linux/mm.h:2150 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1518 [inline] SyS_mmap_pgoff+0x23b/0x5f0 mm/mmap.c:1476 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline] do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124 Freed by task 15007: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x77/0x280 mm/slab.c:3763 __vma_adjust+0x8b9/0x1790 mm/mmap.c:905 vma_merge+0xc5b/0x1070 mm/mmap.c:1150 userfaultfd_release+0x3ba/0x6e0 fs/userfaultfd.c:860 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:112 get_signal+0x1343/0x16d0 kernel/signal.c:2164 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:266 [inline] do_syscall_32_irqs_on arch/x86/entry/common.c:335 [inline] do_fast_syscall_32+0x83e/0xf05 arch/x86/entry/common.c:391 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124 The buggy address belongs to the object at ffff8801d99acca0 which belongs to the cache vm_area_struct of size 200 The buggy address is located 80 bytes inside of 200-byte region [ffff8801d99acca0, ffff8801d99acd68) The buggy address belongs to the page: page:ffffea0007666b00 count:1 mapcount:0 mapping:ffff8801d99ac040 index:0x0 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801d99ac040 0000000000000000 000000010000000f raw: ffffea000764ee60 ffffea0007650fa0 ffff8801dae069c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d99acb80: fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d99acc00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801d99acc80: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d99acd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff8801d99acd80: fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb ==================================================================