================================================================== BUG: KASAN: use-after-free in relay_switch_subbuf+0xa48/0xad0 kernel/relay.c:753 Read of size 8 at addr ffff8880964410d8 by task syz-executor3/28534 CPU: 1 PID: 28534 Comm: syz-executor3 Not tainted 5.0.0-rc3+ #44 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 relay_switch_subbuf+0xa48/0xad0 kernel/relay.c:753 relay_reserve include/linux/relay.h:261 [inline] trace_note.isra.0+0x5b8/0x6e0 kernel/trace/blktrace.c:93 trace_note_tsk kernel/trace/blktrace.c:124 [inline] __blk_add_trace+0xb70/0xe10 kernel/trace/blktrace.c:264 blk_add_trace_rq+0x192/0x210 kernel/trace/blktrace.c:818 blk_add_trace_rq_complete+0x17a/0x1e0 kernel/trace/blktrace.c:847 trace_block_rq_complete include/trace/events/block.h:116 [inline] blk_update_request+0x8e6/0xd10 block/blk-core.c:1433 scsi_end_request+0xf2/0xb70 drivers/scsi/scsi_lib.c:587 scsi_io_completion+0x263/0x1bb0 drivers/scsi/scsi_lib.c:993 scsi_finish_command+0x527/0x910 drivers/scsi/scsi.c:248 scsi_softirq_done+0x45d/0x520 drivers/scsi/scsi_lib.c:1499 blk_done_softirq+0x4ab/0x750 block/blk-softirq.c:37 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0x114/0x1d0 arch/x86/kernel/irq.c:258 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:583 RIP: 0010:__purge_vmap_area_lazy+0x147/0x290 mm/vmalloc.c:680 Code: df 82 38 06 eb 03 4d 89 f4 e8 85 2d c6 ff 49 8d 7c 24 40 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 21 01 00 00 49 8b 44 24 40 <49> 8d 7c 24 08 4c 8d 70 c0 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f RSP: 0018:ffff88809f0df610 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd RAX: ffff88809e94dd40 RBX: 0000000000000002 RCX: ffffc9000a6e3000 RDX: 000000000000afca RSI: ffffffff81bbd34b RDI: ffff88809e94d540 RBP: ffff88809f0df638 R08: 1ffffffff1346ce4 R09: fffffbfff1346ce5 R10: fffffbfff1346ce4 R11: ffffffff89a36723 R12: ffff88809e94d500 R13: dffffc0000000000 R14: ffff88809e94d500 R15: dffffc0000000000 vm_unmap_aliases mm/vmalloc.c:1108 [inline] vm_unmap_aliases+0x4a7/0x620 mm/vmalloc.c:1071 change_page_attr_set_clr+0x287/0xb20 arch/x86/mm/pageattr.c:1698 change_page_attr_clear arch/x86/mm/pageattr.c:1755 [inline] set_memory_ro+0x7b/0xa0 arch/x86/mm/pageattr.c:1982 bpf_jit_binary_lock_ro include/linux/filter.h:696 [inline] bpf_int_jit_compile+0x848/0xef0 arch/x86/net/bpf_jit_comp.c:1168 bpf_prog_select_runtime+0x4c9/0x7f0 kernel/bpf/core.c:1734 bpf_prog_load+0x115b/0x1d00 kernel/bpf/syscall.c:1536 __do_sys_bpf+0xc52/0x4410 kernel/bpf/syscall.c:2618 __se_sys_bpf kernel/bpf/syscall.c:2580 [inline] __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:2580 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7eda7a0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7eda7a16d4 R13: 00000000004be416 R14: 00000000004ce920 R15: 00000000ffffffff Allocated by task 26580: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc mm/kasan/common.c:504 [inline] kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:411 kmem_cache_alloc+0x12d/0x710 mm/slab.c:3543 __d_alloc+0xae/0xbe0 fs/dcache.c:1599 d_alloc+0x99/0x420 fs/dcache.c:1678 d_alloc_parallel+0x11b/0x1f10 fs/dcache.c:2421 __lookup_slow+0x1fa/0x560 fs/namei.c:1654 lookup_one_len+0x1de/0x230 fs/namei.c:2543 start_creating fs/debugfs/inode.c:308 [inline] start_creating+0xbf/0x1e0 fs/debugfs/inode.c:284 __debugfs_create_file+0x65/0x400 fs/debugfs/inode.c:347 debugfs_create_file+0x5a/0x70 fs/debugfs/inode.c:399 kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:616 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3350 [inline] kvm_dev_ioctl+0xb67/0x1a60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3377 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3749 __d_free+0x20/0x30 fs/dcache.c:257 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 The buggy address belongs to the object at ffff888096441080 which belongs to the cache dentry(54:syz3) of size 288 The buggy address is located 88 bytes inside of 288-byte region [ffff888096441080, ffff8880964411a0) The buggy address belongs to the page: page:ffffea0002591040 count:1 mapcount:0 mapping:ffff88808d0a6d80 index:0xffff8880964411e0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002128248 ffffea0002779888 ffff88808d0a6d80 raw: ffff8880964411e0 ffff888096441080 0000000100000002 ffff8880565be0c0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880565be0c0 Memory state around the buggy address: ffff888096440f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888096441000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888096441080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888096441100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888096441180: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb ==================================================================