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BUG: KASAN: slab-out-of-bounds in strset_parse_request+0x4dd/0x530 net/ethtool/strset.c:172
Read of size 8 at addr ffff8880155bc3d8 by task syz-executor.3/10127

CPU: 0 PID: 10127 Comm: syz-executor.3 Not tainted 5.9.0-rc8-next-20201007-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+0x198/0x1fb lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 strset_parse_request+0x4dd/0x530 net/ethtool/strset.c:172
 ethnl_default_parse+0xda/0x130 net/ethtool/netlink.c:282
 ethnl_default_start+0x21f/0x510 net/ethtool/netlink.c:501
 genl_start+0x3cc/0x670 net/netlink/genetlink.c:604
 __netlink_dump_start+0x585/0x900 net/netlink/af_netlink.c:2363
 genl_family_rcv_msg_dumpit+0x1c9/0x310 net/netlink/genetlink.c:697
 genl_family_rcv_msg net/netlink/genetlink.c:780 [inline]
 genl_rcv_msg+0x434/0x580 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2362
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2416
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2449
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de29
Code: 0d b4 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2bd41fec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000029440 RCX: 000000000045de29
RDX: 0000000000000000 RSI: 0000000020000780 RDI: 0000000000000004
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd5b57785f R14: 00007f2bd41ff9c0 R15: 000000000118bf2c

Allocated by task 10127:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3657 [inline]
 __kmalloc+0x27b/0x4d0 mm/slab.c:3666
 kmalloc_array include/linux/slab.h:594 [inline]
 genl_family_rcv_msg_attrs_parse.constprop.0+0xd7/0x280 net/netlink/genetlink.c:543
 genl_start+0x187/0x670 net/netlink/genetlink.c:584
 __netlink_dump_start+0x585/0x900 net/netlink/af_netlink.c:2363
 genl_family_rcv_msg_dumpit+0x1c9/0x310 net/netlink/genetlink.c:697
 genl_family_rcv_msg net/netlink/genetlink.c:780 [inline]
 genl_rcv_msg+0x434/0x580 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2362
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2416
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2449
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880155bc3c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
 32-byte region [ffff8880155bc3c0, ffff8880155bc3e0)
The buggy address belongs to the page:
page:00000000128f6125 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880155bcfc1 pfn:0x155bc
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0000405f08 ffffea000043da08 ffff88800ec40100
raw: ffff8880155bcfc1 ffff8880155bc000 000000010000003b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880155bc280: 00 03 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff8880155bc300: 04 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8880155bc380: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
                                                    ^
 ffff8880155bc400: 00 fc fc fc fc fc fc fc 00 fc fc fc fc fc fc fc
 ffff8880155bc480: 00 fc fc fc fc fc fc fc 00 02 fc fc fc fc fc fc
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