================================================================== BUG: KASAN: use-after-free in __collect_expired_timers include/linux/list.h:729 [inline] BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1569 [inline] BUG: KASAN: use-after-free in __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616 Write of size 8 at addr ffff88003b2e3d48 by task syz-executor0/6393 CPU: 1 PID: 6393 Comm: syz-executor0 Not tainted 4.13.0-next-20170908+ #18 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 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+0x24e/0x340 mm/kasan/report.c:409 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435 __collect_expired_timers include/linux/list.h:729 [inline] collect_expired_timers kernel/time/timer.c:1569 [inline] __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616 run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646 __do_softirq+0x2bb/0xbd0 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d3/0x210 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x177/0x710 arch/x86/kernel/apic/apic.c:1048 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:577 RIP: 0010:unmapped_area_topdown+0x403/0x800 mm/mmap.c:1947 RSP: 0018:ffff88005739fa78 EFLAGS: 00000287 ORIG_RAX: ffffffffffffff10 RAX: 0000000000021000 RBX: ffff88005739fbb0 RCX: 0000000000100000 RDX: 0000000000000000 RSI: 1ffff1000ae73f7b RDI: ffff88006cba19c0 RBP: ffff88005739fb50 R08: 0000000000020022 R09: 0000000000000000 R10: 1ffff1000ae73e9b R11: ffff88005739fdd0 R12: ffff88006cba19a8 R13: ffff88006a158210 R14: dffffc0000000000 R15: 00007f927696a000 vm_unmapped_area include/linux/mm.h:2200 [inline] arch_get_unmapped_area_topdown+0x5f8/0x8a0 arch/x86/kernel/sys_x86_64.c:226 get_unmapped_area+0x18d/0x300 mm/mmap.c:2100 do_mmap+0x2aa/0xd50 mm/mmap.c:1364 do_mmap_pgoff include/linux/mm.h:2151 [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 SYSC_mmap arch/x86/kernel/sys_x86_64.c:99 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:90 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x4472ba RSP: 002b:0000000000a5f788 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00000000004472ba RDX: 0000000000000003 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000082 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 0000000000a5f970 R13: 0000000000708000 R14: 000000000000038c R15: 0000000000000000 Allocated by task 5476: 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 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:535 [inline] kvmalloc_node+0x64/0xd0 mm/util.c:397 kvmalloc include/linux/mm.h:529 [inline] kvzalloc include/linux/mm.h:537 [inline] alloc_netdev_mqs+0x16e/0xed0 net/core/dev.c:8011 tun_set_iff drivers/net/tun.c:2022 [inline] __tun_chr_ioctl+0x12be/0x3d20 drivers/net/tun.c:2276 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2521 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 5476: 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] kfree+0xca/0x250 mm/slab.c:3820 kvfree+0x36/0x60 mm/util.c:416 netdev_freemem net/core/dev.c:7963 [inline] free_netdev+0x2cf/0x360 net/core/dev.c:8125 tun_set_iff drivers/net/tun.c:2105 [inline] __tun_chr_ioctl+0x2cf6/0x3d20 drivers/net/tun.c:2276 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2521 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff88003b2e0940 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff88003b2e0940, ffff88003b2e4940) The buggy address belongs to the page: page:ffffea0000ecb800 count:1 mapcount:0 mapping:ffff88003b2e0940 index:0x0 compound_mapcount: 0 flags: 0x100000000008100(slab|head) raw: 0100000000008100 ffff88003b2e0940 0000000000000000 0000000100000001 raw: ffffea00009c6c20 ffffea0000efa220 ffff88003e802200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88003b2e3c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88003b2e3c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88003b2e3d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88003b2e3d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88003b2e3e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================