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BUG: KASAN: slab-out-of-bounds in ether_addr_equal include/linux/etherdevice.h:322 [inline]
BUG: KASAN: slab-out-of-bounds in ether_addr_equal_unaligned include/linux/etherdevice.h:376 [inline]
BUG: KASAN: slab-out-of-bounds in batadv_compare_eth net/batman-adv/main.h:283 [inline]
BUG: KASAN: slab-out-of-bounds in batadv_interface_tx+0x1638/0x1880 net/batman-adv/soft-interface.c:265
Read of size 4 at addr ffff8880a57dd33f by task syz-executor2/13380

CPU: 0 PID: 13380 Comm: syz-executor2 Not tainted 4.20.0+ #3
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+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 ether_addr_equal include/linux/etherdevice.h:322 [inline]
 ether_addr_equal_unaligned include/linux/etherdevice.h:376 [inline]
 batadv_compare_eth net/batman-adv/main.h:283 [inline]
 batadv_interface_tx+0x1638/0x1880 net/batman-adv/soft-interface.c:265
 __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
 netdev_start_xmit include/linux/netdevice.h:4391 [inline]
 dev_direct_xmit+0x368/0x670 net/core/dev.c:3930
 packet_direct_xmit+0xfb/0x170 net/packet/af_packet.c:246
 packet_snd net/packet/af_packet.c:2932 [inline]
 packet_sendmsg+0x2753/0x6830 net/packet/af_packet.c:2957
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 __sys_sendto+0x387/0x5f0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto net/socket.c:1796 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcbd49d0c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457ec9
RDX: 000000000000000f RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbd49d16d4
R13: 00000000004c53f5 R14: 00000000004d8ef0 R15: 00000000ffffffff

Allocated by task 1:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x152/0x760 mm/slab.c:3620
 kmalloc include/linux/slab.h:546 [inline]
 kzalloc include/linux/slab.h:741 [inline]
 device_private_init drivers/base/core.c:1814 [inline]
 device_add+0xf51/0x1800 drivers/base/core.c:1859
 device_register+0x1e/0x30 drivers/base/core.c:2022
 tty_register_device_attr+0x35c/0x740 drivers/tty/tty_io.c:3131
 tty_register_device drivers/tty/tty_io.c:3065 [inline]
 tty_register_driver+0x4ef/0xb30 drivers/tty/tty_io.c:3336
 legacy_pty_init drivers/tty/pty.c:600 [inline]
 pty_init+0x6b2/0xf1c drivers/tty/pty.c:964
 do_one_initcall+0x129/0x937 init/main.c:889
 do_initcall_level init/main.c:957 [inline]
 do_initcalls init/main.c:965 [inline]
 do_basic_setup init/main.c:983 [inline]
 kernel_init_freeable+0x4db/0x5cf init/main.c:1147
 kernel_init+0x12/0x1c5 init/main.c:1067
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a57dd200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 63 bytes to the right of
 256-byte region [ffff8880a57dd200, ffff8880a57dd300)
The buggy address belongs to the page:
page:ffffea000295f740 count:1 mapcount:0 mapping:ffff88812c3f07c0 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00029ef9c8 ffffea00028ff348 ffff88812c3f07c0
raw: 0000000000000000 ffff8880a57dd0c0 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a57dd200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a57dd280: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff8880a57dd300: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                                        ^
 ffff8880a57dd380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a57dd400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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