================================================================== BUG: KASAN: slab-out-of-bounds in perf_output_read_group kernel/events/core.c:5874 [inline] BUG: KASAN: slab-out-of-bounds in perf_output_read+0xe43/0xfb0 kernel/events/core.c:5909 Read of size 8 at addr ffff8801d2d9fe60 by task syz-executor4/13008 CPU: 0 PID: 13008 Comm: syz-executor4 Not tainted 4.14.76+ #19 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 print_address_description+0x60/0x22b mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409 perf_output_read_group kernel/events/core.c:5874 [inline] perf_output_read+0xe43/0xfb0 kernel/events/core.c:5909 perf_output_sample+0x10dd/0x1780 kernel/events/core.c:5951 __perf_event_output kernel/events/core.c:6261 [inline] perf_event_output_forward+0x121/0x230 kernel/events/core.c:6274 __perf_event_overflow+0x116/0x320 kernel/events/core.c:7510 perf_swevent_overflow+0x166/0x1f0 kernel/events/core.c:7586 perf_swevent_event+0x19c/0x270 kernel/events/core.c:7619 do_perf_sw_event kernel/events/core.c:7727 [inline] ___perf_sw_event+0x296/0x480 kernel/events/core.c:7758 __perf_sw_event+0x3f/0x70 kernel/events/core.c:7770 perf_sw_event include/linux/perf_event.h:1041 [inline] __do_page_fault+0x77f/0xb60 arch/x86/mm/fault.c:1466 page_fault+0x22/0x50 arch/x86/entry/entry_64.S:1104 RIP: 0010:copy_user_enhanced_fast_string+0x7/0x10 arch/x86/lib/copy_user_64.S:180 RSP: 0018:ffff8801b557fb48 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000500 RDX: 0000000000001000 RSI: ffff8801c70deb00 RDI: 0000000020d19000 RBP: 0000000020d18500 R08: 0000000000000000 R09: 0000000000000040 R10: ffffed0038e1bdff R11: ffff8801c70defff R12: ffff8801c70de000 R13: 00007ffffffff000 R14: 0000000020d19500 R15: 0000000000001000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:112 [inline] copyout+0x99/0xc0 lib/iov_iter.c:137 copy_page_to_iter_iovec lib/iov_iter.c:206 [inline] copy_page_to_iter+0x31d/0xd40 lib/iov_iter.c:710 pipe_to_user+0xa6/0x160 fs/splice.c:1237 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x324/0x740 fs/splice.c:626 vmsplice_to_user+0x1bd/0x1e0 fs/splice.c:1272 SYSC_vmsplice fs/splice.c:1353 [inline] SyS_vmsplice+0x12f/0x150 fs/splice.c:1334 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457569 RSP: 002b:00007f025e5c3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000116 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f025e5c46d4 R13: 00000000004c4f4d R14: 00000000004d8520 R15: 00000000ffffffff Allocated by task 13006: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x138/0x300 mm/slub.c:2750 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] alloc_pipe_info+0xad/0x370 fs/pipe.c:633 get_pipe_inode fs/pipe.c:712 [inline] create_pipe_files+0xdc/0x880 fs/pipe.c:745 __do_pipe_flags+0x32/0x210 fs/pipe.c:802 SYSC_pipe2 fs/pipe.c:850 [inline] SyS_pipe2+0x83/0x160 fs/pipe.c:844 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 10569: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1389 [inline] slab_free_freelist_hook mm/slub.c:1410 [inline] slab_free mm/slub.c:2966 [inline] kfree+0xf5/0x310 mm/slub.c:3897 skb_free_head+0x83/0xa0 net/core/skbuff.c:550 skb_release_data+0x495/0x610 net/core/skbuff.c:570 skb_release_all+0x46/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0xc1/0x330 net/core/skbuff.c:701 tun_do_read+0x507/0x12f0 drivers/net/tun.c:1765 tun_chr_read_iter+0xd8/0x1c0 drivers/net/tun.c:1779 call_read_iter include/linux/fs.h:1776 [inline] new_sync_read fs/read_write.c:401 [inline] __vfs_read+0x414/0x5b0 fs/read_write.c:413 vfs_read+0x11e/0x330 fs/read_write.c:447 SYSC_read fs/read_write.c:577 [inline] SyS_read+0xc2/0x1a0 fs/read_write.c:570 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff8801d2d9fb80 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 224 bytes to the right of 512-byte region [ffff8801d2d9fb80, ffff8801d2d9fd80) The buggy address belongs to the page: page:ffffea00074b6780 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001800c000c raw: dead000000000100 dead000000000200 ffff8801da802c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d2d9fd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d2d9fd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d2d9fe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801d2d9fe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d2d9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================