syzbot

netlink: 8 bytes leftover after parsing attributes in process `syz-executor787'.
netlink: 8 bytes leftover after parsing attributes in process `syz-executor787'.
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BUG: KASAN: use-after-free in rtnl_newlink+0x1530/0x15c0 net/core/rtnetlink.c:3149
Read of size 1 at addr ffff88809532c7a8 by task syz-executor787/8094

CPU: 0 PID: 8094 Comm: syz-executor787 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
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
 rtnl_newlink+0x1530/0x15c0 net/core/rtnetlink.c:3149
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351
 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
 __sys_sendmsg net/socket.c:2265 [inline]
 __do_sys_sendmsg net/socket.c:2274 [inline]
 __se_sys_sendmsg net/socket.c:2272 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe5ec064ff9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc8f3d6ff8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000008ce8 RCX: 00007fe5ec064ff9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc8f3d7198 R09: 00007ffc8f3d7198
R10: 00007ffc8f3d7198 R11: 0000000000000246 R12: 00007ffc8f3d700c
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8094:
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node+0x4c/0x70 mm/slab.c:3696
 kmalloc_node include/linux/slab.h:557 [inline]
 kvmalloc_node+0xb4/0xf0 mm/util.c:423
 kvmalloc include/linux/mm.h:577 [inline]
 kvzalloc include/linux/mm.h:585 [inline]
 alloc_netdev_mqs+0x97/0xd50 net/core/dev.c:9152
 rtnl_create_link+0x1d4/0xa40 net/core/rtnetlink.c:2869
 rtnl_newlink+0xf45/0x15c0 net/core/rtnetlink.c:3131
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351
 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
 __sys_sendmsg net/socket.c:2265 [inline]
 __do_sys_sendmsg net/socket.c:2274 [inline]
 __se_sys_sendmsg net/socket.c:2272 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8094:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 kvfree+0x59/0x60 mm/util.c:452
 netdev_freemem net/core/dev.c:9106 [inline]
 free_netdev+0x364/0x410 net/core/dev.c:9257
 device_release+0x76/0x210 drivers/base/core.c:1076
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put+0x28b/0x5d0 lib/kobject.c:708
 put_device drivers/base/core.c:2267 [inline]
 device_unregister+0x35/0xc0 drivers/base/core.c:2379
 register_netdevice+0x901/0x10f0 net/core/dev.c:8791
 nsim_newlink+0x162/0x1c0 drivers/net/netdevsim/netdev.c:555
 rtnl_newlink+0x1030/0x15c0 net/core/rtnetlink.c:3141
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351
 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
 __sys_sendmsg net/socket.c:2265 [inline]
 __do_sys_sendmsg net/socket.c:2274 [inline]
 __se_sys_sendmsg net/socket.c:2272 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809532c240
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 1384 bytes inside of
 8192-byte region [ffff88809532c240, ffff88809532e240)
The buggy address belongs to the page:
page:ffffea000254cb00 count:1 mapcount:0 mapping:ffff88813bff2080 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002c56008 ffff88813bff1b48 ffff88813bff2080
raw: 0000000000000000 ffff88809532c240 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809532c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809532c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809532c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88809532c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809532c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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