================================================================== BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 lib/find_bit.c:107 Read of size 8 at addr ffff8801d9111d10 by task syz-executor559/4542 CPU: 0 PID: 4542 Comm: syz-executor559 Not tainted 4.18.0-rc3-next-20180706+ #1 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 find_first_bit+0xf7/0x100 lib/find_bit.c:107 shrink_slab_memcg mm/vmscan.c:580 [inline] shrink_slab+0x5d0/0xdb0 mm/vmscan.c:672 shrink_node+0x429/0x16a0 mm/vmscan.c:2736 shrink_zones mm/vmscan.c:2965 [inline] do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3027 try_to_free_pages+0x4b2/0xb80 mm/vmscan.c:3242 __perform_reclaim mm/page_alloc.c:3769 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:3790 [inline] __alloc_pages_slowpath+0x953/0x2d00 mm/page_alloc.c:4191 __alloc_pages_nodemask+0xa7c/0xdb0 mm/page_alloc.c:4390 alloc_pages_current+0x10c/0x210 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:492 [inline] depot_save_stack+0x3f0/0x470 lib/stackdepot.c:260 save_stack+0xa9/0xd0 mm/kasan/kasan.c:454 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_node_trace+0x150/0x770 mm/slab.c:3663 kmalloc_node include/linux/slab.h:551 [inline] new_vmap_block mm/vmalloc.c:856 [inline] vb_alloc mm/vmalloc.c:1009 [inline] vm_map_ram+0x663/0xea0 mm/vmalloc.c:1167 ion_heap_clear_pages+0x2a/0x70 drivers/staging/android/ion/ion_heap.c:100 ion_heap_sglist_zero+0x224/0x2d0 drivers/staging/android/ion/ion_heap.c:121 ion_heap_buffer_zero+0xf8/0x150 drivers/staging/android/ion/ion_heap.c:143 ion_system_heap_free+0x1d8/0x250 drivers/staging/android/ion/ion_system_heap.c:163 ion_buffer_destroy+0x15c/0x1c0 drivers/staging/android/ion/ion.c:119 _ion_heap_freelist_drain+0x445/0x6b0 drivers/staging/android/ion/ion_heap.c:199 ion_heap_freelist_drain+0x1f/0x30 drivers/staging/android/ion/ion_heap.c:209 ion_buffer_create drivers/staging/android/ion/ion.c:86 [inline] ion_alloc+0x39b/0xa60 drivers/staging/android/ion/ion.c:409 ion_ioctl+0x216/0x41e drivers/staging/android/ion/ion-ioctl.c:76 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 RIP: 0033:0x4419b9 Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc6766d608 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419b9 RDX: 0000000020000500 RSI: 00000000c0184900 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 R10: 00000000019d9880 R11: 0000000000000213 R12: 000000000000004e R13: 0000000000007802 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4461: 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 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3689 kmalloc_node include/linux/slab.h:555 [inline] kvmalloc_node+0x65/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:557 [inline] kvzalloc include/linux/mm.h:565 [inline] memcg_alloc_shrinker_maps mm/memcontrol.c:386 [inline] mem_cgroup_css_online+0x169/0x3c0 mm/memcontrol.c:4685 online_css+0x10c/0x350 kernel/cgroup/cgroup.c:4768 css_create kernel/cgroup/cgroup.c:4839 [inline] cgroup_apply_control_enable+0x777/0xe90 kernel/cgroup/cgroup.c:2987 cgroup_mkdir+0x88a/0x1170 kernel/cgroup/cgroup.c:5029 kernfs_iop_mkdir+0x159/0x1e0 fs/kernfs/dir.c:1099 vfs_mkdir+0x42e/0x6b0 fs/namei.c:3874 do_mkdirat+0x27b/0x310 fs/namei.c:3897 __do_sys_mkdir fs/namei.c:3913 [inline] __se_sys_mkdir fs/namei.c:3911 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3911 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2869: 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 single_release+0x8f/0xb0 fs/seq_file.c:596 __fput+0x35d/0x930 fs/file_table.c:215 ____fput+0x15/0x20 fs/file_table.c:251 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:192 [inline] exit_to_usermode_loop+0x313/0x370 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801d9111d00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 16 bytes inside of 32-byte region [ffff8801d9111d00, ffff8801d9111d20) The buggy address belongs to the page: page:ffffea0007644440 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d9111fc1 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007604c88 ffffea0007616488 ffff8801da8001c0 raw: ffff8801d9111fc1 ffff8801d9111000 000000010000002d 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d9111c00: 00 04 fc fc fc fc fc fc 00 fc fc fc fc fc fc fc ffff8801d9111c80: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d9111d00: 00 00 05 fc fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8801d9111d80: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc ffff8801d9111e00: 00 01 fc fc fc fc fc fc 00 01 fc fc fc fc fc fc ==================================================================