================================================================== BUG: KASAN: use-after-free in primary_event_id kernel/events/core.c:1316 [inline] BUG: KASAN: use-after-free in perf_output_read_group kernel/events/core.c:5897 [inline] BUG: KASAN: use-after-free in perf_output_read+0x1046/0x1090 kernel/events/core.c:5932 Read of size 8 at addr ffff8880a88ab860 by task syz-executor.0/9508 CPU: 1 PID: 9508 Comm: syz-executor.0 Not tainted 4.14.286-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 primary_event_id kernel/events/core.c:1316 [inline] perf_output_read_group kernel/events/core.c:5897 [inline] perf_output_read+0x1046/0x1090 kernel/events/core.c:5932 perf_output_sample+0xa28/0x16f0 kernel/events/core.c:5974 __perf_event_output kernel/events/core.c:6287 [inline] perf_event_output_forward+0xf8/0x1f0 kernel/events/core.c:6300 __perf_event_overflow+0x113/0x310 kernel/events/core.c:7549 perf_swevent_overflow kernel/events/core.c:7625 [inline] perf_swevent_event+0x299/0x460 kernel/events/core.c:7653 do_perf_sw_event kernel/events/core.c:7766 [inline] ___perf_sw_event+0x2a1/0x480 kernel/events/core.c:7797 __perf_sw_event+0x4f/0x100 kernel/events/core.c:7809 perf_sw_event include/linux/perf_event.h:1046 [inline] __do_page_fault+0x692/0xad0 arch/x86/mm/fault.c:1483 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1123 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:181 RSP: 0018:ffff888063ea7a60 EFLAGS: 00050206 RAX: ffffed100c1ea000 RBX: 0000000000008000 RCX: 000000000000304b RDX: 0000000000008000 RSI: 0000000020f6b000 RDI: ffff888060f4cfb5 RBP: 0000000020f6604b R08: 0000000000000001 R09: ffffed100c1e9fff R10: ffff888060f4ffff R11: 0000000000000000 R12: ffff888060f48000 R13: 00007ffffffff000 R14: 0000000020f6e04b R15: ffff8880ae800200 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:55 [inline] copyin+0x99/0xc0 lib/iov_iter.c:146 _copy_from_iter_full+0x19c/0x760 lib/iov_iter.c:610 copy_from_iter_full include/linux/uio.h:126 [inline] skb_do_copy_data_nocache include/net/sock.h:1892 [inline] skb_copy_to_page_nocache include/net/sock.h:1918 [inline] tcp_sendmsg_locked+0x23fc/0x2ef0 net/ipv4/tcp.c:1360 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457 inet_sendmsg+0x11a/0x4e0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1c7/0x2c0 net/socket.c:1731 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f9571c2b109 RSP: 002b:00007f95705a0168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9571d3df60 RCX: 00007f9571c2b109 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006 RBP: 00007f9571c8505d R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee8a7929f R14: 00007f95705a0300 R15: 0000000000022000 Allocated by task 0: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0x96/0x510 net/core/skbuff.c:205 __napi_alloc_skb+0x57/0x2d0 net/core/skbuff.c:478 napi_alloc_skb include/linux/skbuff.h:2720 [inline] page_to_skb+0x7b/0x820 drivers/net/virtio_net.c:323 receive_mergeable drivers/net/virtio_net.c:723 [inline] receive_buf+0x1f71/0x4d70 drivers/net/virtio_net.c:828 virtnet_receive drivers/net/virtio_net.c:1102 [inline] virtnet_poll+0x4b7/0x960 drivers/net/virtio_net.c:1193 napi_poll net/core/dev.c:5604 [inline] net_rx_action+0x466/0xfd0 net/core/dev.c:5670 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 Freed by task 7971: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 skb_free_head net/core/skbuff.c:563 [inline] skb_release_data+0x5f6/0x820 net/core/skbuff.c:583 skb_release_all net/core/skbuff.c:640 [inline] __kfree_skb net/core/skbuff.c:654 [inline] kfree_skb_partial+0x75/0x90 net/core/skbuff.c:4829 tcp_rcv_established+0x164e/0x1a50 net/ipv4/tcp_input.c:5564 tcp_v4_do_rcv+0x541/0x7d0 net/ipv4/tcp_ipv4.c:1487 sk_backlog_rcv include/net/sock.h:923 [inline] __release_sock+0x12a/0x350 net/core/sock.c:2284 release_sock+0x54/0x1b0 net/core/sock.c:2822 tcp_recvmsg+0x66d/0x1d50 net/ipv4/tcp.c:2015 inet_recvmsg+0xef/0x4d0 net/ipv4/af_inet.c:793 sock_recvmsg_nosec net/socket.c:819 [inline] sock_recvmsg net/socket.c:826 [inline] sock_recvmsg net/socket.c:822 [inline] sock_read_iter+0x2be/0x3f0 net/socket.c:903 call_read_iter include/linux/fs.h:1774 [inline] new_sync_read fs/read_write.c:401 [inline] __vfs_read+0x449/0x620 fs/read_write.c:413 vfs_read+0x139/0x340 fs/read_write.c:447 SYSC_read fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 fs/read_write.c:567 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a88ab800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 96 bytes inside of 512-byte region [ffff8880a88ab800, ffff8880a88aba00) The buggy address belongs to the page: page:ffffea0002a22ac0 count:1 mapcount:0 mapping:ffff8880a88ab080 index:0xffff8880a88ab580 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880a88ab080 ffff8880a88ab580 0000000100000001 raw: ffffea0002d37be0 ffffea0002cc4c60 ffff88813fe74940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a88ab700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a88ab780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a88ab800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a88ab880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a88ab900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================