syzbot

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BUG: KASAN: stack-out-of-bounds in memset include/linux/string.h:410 [inline]
BUG: KASAN: stack-out-of-bounds in ax25_getname+0x58/0x7a0 net/ax25/af_ax25.c:1405
Write of size 72 at addr ffffc90002337c78 by task syz-executor.0/9319

CPU: 0 PID: 9319 Comm: syz-executor.0 Not tainted 5.4.0-next-20191204-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memset+0x24/0x40 mm/kasan/common.c:108
 memset include/linux/string.h:410 [inline]
 ax25_getname+0x58/0x7a0 net/ax25/af_ax25.c:1405
 get_raw_socket drivers/vhost/net.c:1451 [inline]
 get_socket drivers/vhost/net.c:1507 [inline]
 vhost_net_set_backend drivers/vhost/net.c:1542 [inline]
 vhost_net_ioctl+0x120a/0x1960 drivers/vhost/net.c:1733
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa37e85bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679
RDX: 0000000020d7c000 RSI: 000000004008af30 RDI: 0000000000000003
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa37e85c6d4
R13: 00000000004c62d7 R14: 00000000004dc718 R15: 00000000ffffffff


addr ffffc90002337c78 is located in stack of task syz-executor.0/9319 at offset 128 in frame:
 vhost_net_ioctl+0x0/0x1960 drivers/vhost/net.c:389

this frame has 4 objects:
 [48, 52) 'r'
 [64, 72) 'features'
 [96, 104) 'backend'
 [128, 180) 'uaddr'

Memory state around the buggy address:
 ffffc90002337b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
 ffffc90002337c00: f1 f1 f1 f1 f1 04 f2 00 f2 f2 f2 00 f2 f2 f2 00
>ffffc90002337c80: 00 00 00 00 00 04 f3 f3 f3 f3 f3 00 00 00 00 00
                                  ^
 ffffc90002337d00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffffc90002337d80: 00 f2 f2 f2 00 00 00 f2 f2 f2 f2 f2 00 00 00 00
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