================================================================== BUG: KASAN: use-after-free in perf_output_read_group kernel/events/core.c:5874 [inline] BUG: KASAN: use-after-free in perf_output_read+0xe4d/0xfb0 kernel/events/core.c:5909 Read of size 8 at addr ffff8801c422f288 by task syz-executor0/9493 CPU: 0 PID: 9493 Comm: syz-executor0 Not tainted 4.14.76+ #20 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+0xe4d/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:ffff8801cf11fb48 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000500 RDX: 0000000000001000 RSI: ffff8801d1144b00 RDI: 000000002074b000 RBP: 000000002074a500 R08: 0000000000000000 R09: 0000000000000040 R10: ffffed003a2289ff R11: ffff8801d1144fff R12: ffff8801d1144000 R13: 00007ffffffff000 R14: 000000002074b500 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:00007f7bad085c78 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: 00007f7bad0866d4 R13: 00000000004c4f4d R14: 00000000004d8520 R15: 00000000ffffffff Allocated by task 190: 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 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2731 [inline] __kmalloc_track_caller+0x104/0x300 mm/slub.c:4288 __kmalloc_reserve.isra.8+0x2f/0xc0 net/core/skbuff.c:137 __alloc_skb+0x105/0x550 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] kobject_uevent_env+0x645/0xc40 lib/kobject_uevent.c:476 kobject_synth_uevent+0x6ee/0x838 lib/kobject_uevent.c:205 uevent_store+0x21/0x60 drivers/base/core.c:994 dev_attr_store+0x57/0x80 drivers/base/core.c:714 sysfs_kf_write+0x10a/0x160 fs/sysfs/file.c:141 kernfs_fop_write+0x28b/0x440 fs/kernfs/file.c:316 __vfs_write+0xf4/0x5c0 fs/read_write.c:482 vfs_write+0x17f/0x4d0 fs/read_write.c:546 SYSC_write fs/read_write.c:593 [inline] SyS_write+0xc2/0x1a0 fs/read_write.c:585 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 190: 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 netlink_broadcast_filtered+0x2b7/0xa30 net/netlink/af_netlink.c:1488 kobject_uevent_env+0x793/0xc40 lib/kobject_uevent.c:492 kobject_synth_uevent+0x6ee/0x838 lib/kobject_uevent.c:205 uevent_store+0x21/0x60 drivers/base/core.c:994 dev_attr_store+0x57/0x80 drivers/base/core.c:714 sysfs_kf_write+0x10a/0x160 fs/sysfs/file.c:141 kernfs_fop_write+0x28b/0x440 fs/kernfs/file.c:316 __vfs_write+0xf4/0x5c0 fs/read_write.c:482 vfs_write+0x17f/0x4d0 fs/read_write.c:546 SYSC_write fs/read_write.c:593 [inline] SyS_write+0xc2/0x1a0 fs/read_write.c:585 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 ffff8801c422f180 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8801c422f180, ffff8801c422f380) The buggy address belongs to the page: page:ffffea0007108b80 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001000c000c raw: 0000000000000000 0000000b00000001 ffff8801d6402c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c422f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c422f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c422f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c422f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c422f380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================