================================================================== BUG: KASAN: use-after-free in packet_rcv+0x5aa/0x1490 net/packet/af_packet.c:2104 Read of size 1 at addr ffff88804972706c by task syz-executor.4/24968 CPU: 1 PID: 24968 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #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+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 packet_rcv+0x5aa/0x1490 net/packet/af_packet.c:2104 deliver_skb net/core/dev.c:1956 [inline] dev_queue_xmit_nit+0x24d/0xa20 net/core/dev.c:2012 xmit_one net/core/dev.c:3252 [inline] dev_hard_start_xmit+0xaa/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 hsr_xmit net/hsr/hsr_forward.c:237 [inline] hsr_forward_do net/hsr/hsr_forward.c:295 [inline] hsr_forward_skb+0xd2d/0x1c30 net/hsr/hsr_forward.c:373 send_hsr_supervision_frame+0x917/0xf70 net/hsr/hsr_device.c:321 hsr_announce+0x125/0x3a0 net/hsr/hsr_device.c:350 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:rcu_read_unlock_special+0x456/0xfc0 kernel/rcu/tree_plugin.h:601 Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 bd 09 00 00 48 83 3d ee 24 a0 08 00 0f 84 37 06 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e 41 5f c3 c3 48 RSP: 0018:ffff8880b2c972f8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3051 RBX: 0000000000000000 RCX: 1ffff11013833dc5 RDX: dffffc0000000000 RSI: ffff88809c19ee30 RDI: 0000000000000286 RBP: ffff88809c19e8f4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809c19e580 R13: ffff88809c19e8f6 R14: ffff88809c19e8f5 R15: ffffffff89f88280 __rcu_read_unlock+0x158/0x160 kernel/rcu/tree_plugin.h:428 rcu_read_unlock include/linux/rcupdate.h:680 [inline] is_bpf_text_address+0xdf/0x1b0 kernel/bpf/core.c:548 kernel_text_address kernel/extable.c:152 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:122 __kernel_text_address+0x9/0x30 kernel/extable.c:107 unwind_get_return_address arch/x86/kernel/unwind_orc.c:297 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:292 __save_stack_trace+0xaf/0x190 arch/x86/kernel/stacktrace.c:45 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 kmem_cache_zalloc include/linux/slab.h:699 [inline] __kernfs_new_node+0xd2/0x680 fs/kernfs/dir.c:633 kernfs_new_node+0x92/0x120 fs/kernfs/dir.c:693 __kernfs_create_file+0x51/0x340 fs/kernfs/file.c:992 sysfs_add_file_mode_ns+0x226/0x540 fs/sysfs/file.c:307 create_files fs/sysfs/group.c:63 [inline] internal_create_group+0x355/0xb20 fs/sysfs/group.c:147 sysfs_create_group fs/sysfs/group.c:173 [inline] sysfs_create_groups fs/sysfs/group.c:200 [inline] sysfs_create_groups+0x98/0x140 fs/sysfs/group.c:190 device_add_groups drivers/base/core.c:1301 [inline] device_add_attrs drivers/base/core.c:1455 [inline] device_add+0x8cf/0x16d0 drivers/base/core.c:2139 register_disk block/genhd.c:605 [inline] __device_add_disk+0x62e/0x10c0 block/genhd.c:723 add_disk include/linux/genhd.h:409 [inline] loop_add+0x628/0x8a0 drivers/block/loop.c:2048 loop_control_ioctl drivers/block/loop.c:2149 [inline] loop_control_ioctl+0x16c/0x480 drivers/block/loop.c:2131 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fbae4bae109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbae3523168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbae4cc0f60 RCX: 00007fbae4bae109 RDX: 000000000000000b RSI: 0000000000004c80 RDI: 0000000000000005 RBP: 00007fbae4c0808d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffde74f6d7f R14: 00007fbae3523300 R15: 0000000000022000 Allocated by task 24963: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1483 sk_alloc+0x36/0xec0 net/core/sock.c:1537 packet_create+0x117/0x850 net/packet/af_packet.c:3259 __sock_create+0x3d8/0x740 net/socket.c:1365 sock_create net/socket.c:1416 [inline] __sys_socket+0xef/0x200 net/socket.c:1458 __do_sys_socket net/socket.c:1467 [inline] __se_sys_socket net/socket.c:1465 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1465 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24972: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 sk_prot_free net/core/sock.c:1520 [inline] __sk_destruct+0x684/0x8a0 net/core/sock.c:1602 sk_destruct net/core/sock.c:1617 [inline] __sk_free+0x165/0x3b0 net/core/sock.c:1628 sk_free+0x3b/0x50 net/core/sock.c:1639 sock_put include/net/sock.h:1713 [inline] packet_release+0x890/0xb70 net/packet/af_packet.c:3088 __sock_release+0xcd/0x2a0 net/socket.c:599 sock_close+0x15/0x20 net/socket.c:1214 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888049726940 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 1836 bytes inside of 4096-byte region [ffff888049726940, ffff888049727940) The buggy address belongs to the page: page:ffffea000125c980 count:1 mapcount:0 mapping:ffff88813bff0dc0 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea00011d5188 ffffea0001304708 ffff88813bff0dc0 raw: 0000000000000000 ffff888049726940 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888049726f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888049726f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888049727000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888049727080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888049727100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 7 bytes skipped: 0: df 48 c1 fisttps -0x3f(%rax) 3: e8 03 80 3c 10 callq 0x103c800b 8: 00 0f add %cl,(%rdi) a: 85 bd 09 00 00 48 test %edi,0x48000009(%rbp) 10: 83 3d ee 24 a0 08 00 cmpl $0x0,0x8a024ee(%rip) # 0x8a02505 17: 0f 84 37 06 00 00 je 0x654 1d: 48 8b 3c 24 mov (%rsp),%rdi 21: 57 push %rdi 22: 9d popfq * 23: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 28: 48 83 c4 40 add $0x40,%rsp 2c: 5b pop %rbx 2d: 5d pop %rbp 2e: 41 5c pop %r12 30: 41 5d pop %r13 32: 41 5e pop %r14 34: 41 5f pop %r15 36: c3 retq 37: c3 retq 38: 48 rex.W