syzbot

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BUG: KASAN: stack-out-of-bounds in memset include/linux/string.h:366 [inline]
BUG: KASAN: stack-out-of-bounds in ax25_getname+0x58/0x7a0 net/ax25/af_ax25.c:1405
Write of size 72 at addr ffffc900020c7e00 by task syz-executor973/10753

CPU: 1 PID: 10753 Comm: syz-executor973 Not tainted 5.6.0-rc2-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/0x32 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:641
 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:366 [inline]
 ax25_getname+0x58/0x7a0 net/ax25/af_ax25.c:1405
 get_raw_socket drivers/vhost/net.c:1433 [inline]
 get_socket drivers/vhost/net.c:1489 [inline]
 vhost_net_set_backend drivers/vhost/net.c:1524 [inline]
 vhost_net_ioctl+0x1213/0x1960 drivers/vhost/net.c:1715
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440259
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb9862cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
RDX: 0000000020f1dff8 RSI: 000000004008af30 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401ae0
R13: 0000000000401b70 R14: 0000000000000000 R15: 0000000000000000


addr ffffc900020c7e00 is located in stack of task syz-executor973/10753 at offset 128 in frame:
 vhost_net_ioctl+0x0/0x1960 drivers/vhost/net.c:386

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

Memory state around the buggy address:
 ffffc900020c7d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900020c7d80: f1 f1 f1 f1 f1 f1 04 f2 00 f2 f2 f2 00 f2 f2 f2
>ffffc900020c7e00: 00 00 00 00 00 00 04 f3 f3 f3 f3 f3 00 00 00 00
                                     ^
 ffffc900020c7e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900020c7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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