audit: type=1326 audit(186.694:2917): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=12620 comm="syz-executor6" exe="/root/syz-executor6" sig=9 arch=c000003e syscall=202 compat=0 ip=0x455ab9 code=0x0 ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:188 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:203 [inline] BUG: KASAN: use-after-free in shrink_slab_memcg mm/vmscan.c:595 [inline] BUG: KASAN: use-after-free in shrink_slab+0xa04/0xa60 mm/vmscan.c:671 Read of size 8 at addr ffff880191715318 by task syz-executor4/12684 CPU: 0 PID: 12684 Comm: syz-executor4 Not tainted 4.18.0-rc4-next-20180713+ #7 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+0x1c9/0x2b4 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+0x242/0x30d mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:188 [inline] list_empty include/linux/list.h:203 [inline] shrink_slab_memcg mm/vmscan.c:595 [inline] shrink_slab+0xa04/0xa60 mm/vmscan.c:671 shrink_node+0x429/0x16a0 mm/vmscan.c:2735 shrink_zones mm/vmscan.c:2964 [inline] do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3324 memory_high_write+0x283/0x310 mm/memcontrol.c:5611 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3502 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316 __vfs_write+0x117/0x9d0 fs/read_write.c:485 __kernel_write+0x10c/0x370 fs/read_write.c:506 write_pipe_buf+0x181/0x240 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38e/0x7c0 fs/splice.c:627 splice_from_pipe+0x1ea/0x340 fs/splice.c:662 default_file_splice_write+0x3c/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x128/0x190 fs/splice.c:1019 splice_direct_to_actor+0x318/0x8f0 fs/splice.c:974 do_splice_direct+0x2d4/0x420 fs/splice.c:1062 do_sendfile+0x62a/0xe20 fs/read_write.c:1440 __do_sys_sendfile64 fs/read_write.c:1495 [inline] __se_sys_sendfile64 fs/read_write.c:1487 [inline] __x64_sys_sendfile64+0x15d/0x250 fs/read_write.c:1487 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455ab9 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fae077d1c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fae077d26d4 RCX: 0000000000455ab9 RDX: 0000000020000040 RSI: 0000000000000014 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c0d79 R14: 00000000004d1380 R15: 0000000000000000 Allocated by task 11624: 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:513 [inline] kzalloc include/linux/slab.h:707 [inline] kvm_uevent_notify_change.part.32+0xa1/0x440 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3885 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3871 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3209 [inline] kvm_dev_ioctl+0x15fa/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3231 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11624: 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 kvm_uevent_notify_change.part.32+0x300/0x440 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3913 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3871 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3209 [inline] kvm_dev_ioctl+0x15fa/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3231 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff880191714bc0 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 1880 bytes inside of 4096-byte region [ffff880191714bc0, ffff880191715bc0) The buggy address belongs to the page: page:ffffea000645c500 count:1 mapcount:0 mapping:ffff8801da800dc0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffffea0006c00288 ffffea00066aad88 ffff8801da800dc0 raw: 0000000000000000 ffff880191714bc0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880191715200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880191715280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880191715300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880191715380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880191715400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================