netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:193 [inline] BUG: KASAN: use-after-free in dev_queue_xmit_nit+0x87a/0xa00 net/core/dev.c:2008 Read of size 8 at addr ffff8880a0ac4c70 by task syz-executor.1/8165 CPU: 1 PID: 8165 Comm: syz-executor.1 Not tainted 4.19.117-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256 audit: type=1800 audit(1587481189.056:14): pid=8172 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=15811 res=0 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396 __read_once_size include/linux/compiler.h:193 [inline] dev_queue_xmit_nit+0x87a/0xa00 net/core/dev.c:2008 xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0xa6/0x950 net/core/dev.c:3276 __dev_queue_xmit+0x270f/0x3040 net/core/dev.c:3846 hsr_xmit net/hsr/hsr_forward.c:237 [inline] hsr_forward_do net/hsr/hsr_forward.c:295 [inline] hsr_forward_skb+0xcf7/0x1bb0 net/hsr/hsr_forward.c:373 send_hsr_supervision_frame+0x920/0xfb0 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:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0x5d0/0x1540 kernel/time/timer.c:1697 __do_softirq+0x26c/0x93c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17b/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:192 Code: c0 58 56 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 61 43 b2 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 06 88 26 fa 65 8b 05 bf da e1 78 85 c0 74 02 5d RSP: 0018:ffff88804386f838 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a4acb RBX: ffff88809f178280 RCX: 1ffff11013e2f16f RDX: dffffc0000000000 RSI: ffff88809f178b80 RDI: ffff88809f178b04 RBP: ffff8880ae72c280 R08: ffff88809f178280 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae72c280 R13: ffff8880a92ec6c0 R14: ffff888089c26e00 R15: 0000000000000000 finish_lock_switch kernel/sched/core.c:2576 [inline] finish_task_switch+0x146/0x780 kernel/sched/core.c:2676 context_switch kernel/sched/core.c:2829 [inline] __schedule+0x86e/0x1d80 kernel/sched/core.c:3515 netlink: 'syz-executor.5': attribute type 1 has an invalid length. preempt_schedule_common+0x4a/0xc0 kernel/sched/core.c:3639 ___preempt_schedule+0x16/0x18 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xb7/0xe0 kernel/locking/spinlock.c:184 rcu_read_unlock_special+0x666/0xeb0 kernel/rcu/tree_plugin.h:587 __rcu_read_unlock+0x158/0x160 kernel/rcu/tree_plugin.h:428 syz-executor.0 uses obsolete (PF_INET,SOCK_PACKET) rcu_read_unlock include/linux/rcupdate.h:680 [inline] ext4_get_group_desc+0x1d6/0x4f0 fs/ext4/balloc.c:284 __ext4_get_inode_loc+0x196/0x1110 fs/ext4/inode.c:4595 ext4_get_inode_loc fs/ext4/inode.c:4721 [inline] ext4_reserve_inode_write+0xed/0x260 fs/ext4/inode.c:5924 ext4_mark_inode_dirty+0x15b/0x890 fs/ext4/inode.c:6091 batman_adv: batadv0: Adding interface: veth3 ext4_unlink fs/ext4/namei.c:3076 [inline] ext4_unlink+0xc87/0x1050 fs/ext4/namei.c:3026 vfs_unlink+0x2cc/0x4f0 fs/namei.c:4002 batman_adv: batadv0: The MTU of interface veth3 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. do_unlinkat+0x3c4/0x680 fs/namei.c:4065 batman_adv: batadv0: Not using interface veth3 (retrying later): interface not active do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f14d75b6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000509ac0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c40 R14: 00000000004c9de2 R15: 00007f14d75b76d4 Allocated by task 8164: netlink: 'syz-executor.5': attribute type 1 has an invalid length. set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15b/0x770 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] sk_prot_alloc+0x18c/0x2d0 net/core/sock.c:1466 sk_alloc+0x36/0xf50 net/core/sock.c:1520 batman_adv: batadv0: Adding interface: veth5 packet_create+0x115/0x840 net/packet/af_packet.c:3247 __sock_create+0x3d5/0x740 net/socket.c:1276 sock_create net/socket.c:1316 [inline] __sys_socket+0xef/0x200 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1353 batman_adv: batadv0: The MTU of interface veth5 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8159: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521 __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 sk_prot_free net/core/sock.c:1503 [inline] __sk_destruct+0x579/0x780 net/core/sock.c:1583 sk_destruct+0xb9/0xf0 net/core/sock.c:1598 __sk_free+0xc2/0x2e0 net/core/sock.c:1609 sk_free+0x3b/0x50 net/core/sock.c:1620 sock_put include/net/sock.h:1707 [inline] packet_release+0x93f/0xc70 net/packet/af_packet.c:3076 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 batman_adv: batadv0: Not using interface veth5 (retrying later): interface not active __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167 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 ffff8880a0ac4480 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 2032 bytes inside of 2048-byte region [ffff8880a0ac4480, ffff8880a0ac4c80) The buggy address belongs to the page: page:ffffea000282b100 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea000282f008 ffffea000283fd88 ffff88812c39cc40 raw: 0000000000000000 ffff8880a0ac4480 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0ac4b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0ac4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a0ac4c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a0ac4c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a0ac4d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================