================================================================== BUG: KASAN: use-after-free in relay_switch_subbuf+0x8be/0x920 kernel/relay.c:755 Read of size 8 at addr ffff888084100398 by task udevd/19680 CPU: 1 PID: 19680 Comm: udevd Not tainted 5.4.0-rc1 #0 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:634 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 relay_switch_subbuf+0x8be/0x920 kernel/relay.c:755 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+0x185/0x1f0 kernel/trace/blktrace.c:813 blk_add_trace_rq_complete+0x17a/0x1e0 kernel/trace/blktrace.c:842 trace_block_rq_complete include/trace/events/block.h:116 [inline] blk_update_request+0x9e7/0xdc0 block/blk-core.c:1435 scsi_end_request+0x7f/0x840 drivers/scsi/scsi_lib.c:579 scsi_io_completion+0x20a/0x1420 drivers/scsi/scsi_lib.c:963 scsi_finish_command+0x3b7/0x670 drivers/scsi/scsi.c:228 scsi_softirq_done+0x326/0x3b0 drivers/scsi/scsi_lib.c:1477 blk_done_softirq+0x2fe/0x4d0 block/blk-softirq.c:37 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0xe3/0x280 arch/x86/kernel/irq.c:263 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607 RIP: 0010:unwind_get_return_address+0x32/0xa0 arch/x86/kernel/unwind_frame.c:16 Code: ff df 48 89 fa 55 48 c1 ea 03 48 89 e5 41 54 53 0f b6 14 02 48 89 f8 48 89 fb 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 55 8b 03 <85> c0 75 07 5b 31 c0 41 5c 5d c3 4c 8d 63 48 48 b8 00 00 00 00 00 RSP: 0018:ffff888035f17600 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd RAX: 0000000000000001 RBX: ffff888035f17620 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 1ffff11006be2e00 RDI: ffff888035f17620 RBP: ffff888035f17610 R08: 0000000000000001 R09: ffff888035f17678 R10: ffff888035f17648 R11: ffff888035f17658 R12: ffff888035f176d8 R13: 0000000000000000 R14: ffff888061a60700 R15: ffff8880aa591540 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123 save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 vm_area_dup+0x21/0x170 kernel/fork.c:356 dup_mmap kernel/fork.c:541 [inline] dup_mm+0x549/0x1430 kernel/fork.c:1361 copy_mm kernel/fork.c:1417 [inline] copy_process+0x26c5/0x6860 kernel/fork.c:2012 _do_fork+0x146/0xfa0 kernel/fork.c:2366 __do_sys_clone kernel/fork.c:2521 [inline] __se_sys_clone kernel/fork.c:2502 [inline] __x64_sys_clone+0x18d/0x250 kernel/fork.c:2502 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f8398b1af46 Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 14 25 10 00 00 00 31 d2 49 81 c2 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 31 01 00 00 85 c0 41 89 c4 0f 85 3b 01 00 RSP: 002b:00007fff840608f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fff840608f0 RCX: 00007f8398b1af46 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fff84060950 R08: 0000000000004ce0 R09: 0000000000004ce0 R10: 00007f8399437a70 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff84060910 R14: 0000000000000005 R15: 0000000000000005 Allocated by task 8842: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 __d_alloc+0x2e/0x8c0 fs/dcache.c:1688 d_alloc+0x4d/0x280 fs/dcache.c:1767 d_alloc_parallel+0xf4/0x1c30 fs/dcache.c:2519 lookup_open+0x525/0x1a90 fs/namei.c:3137 do_last fs/namei.c:3314 [inline] path_openat+0x1eb2/0x46d0 fs/namei.c:3525 do_filp_open+0x1a1/0x280 fs/namei.c:3555 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_sys_open fs/open.c:1115 [inline] __se_sys_open fs/open.c:1110 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1110 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24600: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 __d_free+0x20/0x30 fs/dcache.c:271 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2157 [inline] rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386 __do_softirq+0x262/0x98c kernel/softirq.c:292 The buggy address belongs to the object at ffff888084100340 which belongs to the cache dentry(33:syz3) of size 288 The buggy address is located 88 bytes inside of 288-byte region [ffff888084100340, ffff888084100460) The buggy address belongs to the page: page:ffffea0002104000 refcount:1 mapcount:0 mapping:ffff88808ee43000 index:0xffff888084100a20 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea000256a9c8 ffffea00024df0c8 ffff88808ee43000 raw: ffff888084100a20 ffff888084100080 0000000100000009 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888084100280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888084100300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff888084100380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888084100400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888084100480: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================