================================================================== 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 ffff88809cf67620 by task syz-executor.4/13509 CPU: 0 PID: 13509 Comm: syz-executor.4 Not tainted 4.14.262-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:ffff88806a8bfa60 EFLAGS: 00050206 RAX: ffffed100d5c4000 RBX: 0000000000008000 RCX: 0000000000003acb RDX: 0000000000008000 RSI: 0000000020eea000 RDI: ffff88806ae1c535 RBP: 0000000020ee5acb R08: 0000000000000001 R09: ffffed100d5c3fff R10: ffff88806ae1ffff R11: 0000000000000000 R12: ffff88806ae18000 R13: 00007ffffffff000 R14: 0000000020eedacb R15: ffff888092330d40 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:608 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: 0033:0x7fa1693abfe9 RSP: 002b:00007fa167d21168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fa1694bef60 RCX: 00007fa1693abfe9 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 000000000000000e RBP: 00007fa16940608d R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeb7bbc53f R14: 00007fa167d21300 R15: 0000000000022000 Allocated by task 11991: 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 alloc_skb include/linux/skbuff.h:980 [inline] alloc_skb_with_frags+0x85/0x500 net/core/skbuff.c:5258 sock_alloc_send_pskb+0x577/0x6d0 net/core/sock.c:2101 bt_skb_send_alloc include/net/bluetooth/bluetooth.h:347 [inline] l2cap_sock_alloc_skb_cb+0xa6/0x3c0 net/bluetooth/l2cap_sock.c:1412 l2cap_create_iframe_pdu net/bluetooth/l2cap_core.c:2282 [inline] l2cap_segment_sdu net/bluetooth/l2cap_core.c:2354 [inline] l2cap_chan_send+0x1b94/0x3800 net/bluetooth/l2cap_core.c:2566 l2cap_sock_sendmsg+0x1cd/0x280 net/bluetooth/l2cap_sock.c:983 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x326/0x800 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 11991: 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+0xe7/0x390 net/core/skbuff.c:672 __skb_queue_purge include/linux/skbuff.h:2650 [inline] l2cap_segment_sdu net/bluetooth/l2cap_core.c:2357 [inline] l2cap_chan_send+0x225a/0x3800 net/bluetooth/l2cap_core.c:2566 l2cap_sock_sendmsg+0x1cd/0x280 net/bluetooth/l2cap_sock.c:983 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x326/0x800 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 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 ffff88809cf675c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 96 bytes inside of 512-byte region [ffff88809cf675c0, ffff88809cf677c0) The buggy address belongs to the page: page:ffffea000273d9c0 count:1 mapcount:0 mapping:ffff88809cf670c0 index:0xffff88809cf67340 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff88809cf670c0 ffff88809cf67340 0000000100000001 raw: ffffea00026bd8a0 ffffea00026b8160 ffff88813fe74940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809cf67500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88809cf67580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff88809cf67600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809cf67680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809cf67700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================