KASAN: vmalloc-out-of-bounds Read in tipc_nl_node_dump_monitor_peer

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4e15507f libbpf: Forward-declare bpf_stats_type for system..
git tree: bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=1227a0ad100000
kernel config: https://syzkaller.appspot.com/x/.config?x=dcc6334acae363d4
dashboard link: https://syzkaller.appspot.com/bug?extid=80cad1e3cb4c41cde6ff
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155fef15100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127acae9100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+80cad1...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in nla_len include/net/netlink.h:1135 [inline]
BUG: KASAN: vmalloc-out-of-bounds in nla_parse_nested_deprecated include/net/netlink.h:1218 [inline]
BUG: KASAN: vmalloc-out-of-bounds in tipc_nl_node_dump_monitor_peer+0x4da/0x590 net/tipc/node.c:2788
Read of size 2 at addr ffffc90004959024 by task syz-executor857/7189

CPU: 1 PID: 7189 Comm: syz-executor857 Not tainted 5.8.0-rc1-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+0x18f/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
nla_len include/net/netlink.h:1135 [inline]
nla_parse_nested_deprecated include/net/netlink.h:1218 [inline]
tipc_nl_node_dump_monitor_peer+0x4da/0x590 net/tipc/node.c:2788
genl_lock_dumpit+0x7f/0xb0 net/netlink/genetlink.c:575
netlink_dump+0x4cd/0xf60 net/netlink/af_netlink.c:2245
__netlink_dump_start+0x643/0x900 net/netlink/af_netlink.c:2353
genl_family_rcv_msg_dumpit+0x2ac/0x310 net/netlink/genetlink.c:638
genl_family_rcv_msg net/netlink/genetlink.c:733 [inline]
genl_rcv_msg+0x797/0x9e0 net/netlink/genetlink.c:753
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
genl_rcv+0x24/0x40 net/netlink/genetlink.c:764
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446859
Code: Bad RIP value.
RSP: 002b:00007f102ce25d98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446859
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 4002001060fc2413 R14: 0d94638c64805ad2 R15: 0f05002d0000022e


Memory state around the buggy address:
ffffc90004958f00: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90004958f80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
>ffffc90004959000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
^
ffffc90004959080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90004959100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered crash:
KASAN: vmalloc-out-of-bounds Read in tipc_nl_node_dump_monitor_peer

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in nla_len include/net/netlink.h:1135 [inline]
BUG: KASAN: vmalloc-out-of-bounds in nla_parse_nested_deprecated include/net/netlink.h:1218 [inline]
BUG: KASAN: vmalloc-out-of-bounds in tipc_nl_node_dump_monitor_peer+0x4da/0x590 net/tipc/node.c:2788

Read of size 2 at addr ffffc90005f1d024 by task syz-executor.0/8288

CPU: 0 PID: 8288 Comm: syz-executor.0 Not tainted 5.8.0-rc1-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+0x18f/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
nla_len include/net/netlink.h:1135 [inline]
nla_parse_nested_deprecated include/net/netlink.h:1218 [inline]
tipc_nl_node_dump_monitor_peer+0x4da/0x590 net/tipc/node.c:2788
genl_lock_dumpit+0x7f/0xb0 net/netlink/genetlink.c:575

netlink_dump+0x479/0xeb0 net/netlink/af_netlink.c:2246
__netlink_dump_start+0x610/0x900 net/netlink/af_netlink.c:2348

genl_family_rcv_msg_dumpit+0x2ac/0x310 net/netlink/genetlink.c:638
genl_family_rcv_msg net/netlink/genetlink.c:733 [inline]
genl_rcv_msg+0x797/0x9e0 net/netlink/genetlink.c:753

netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2466

genl_rcv+0x24/0x40 net/netlink/genetlink.c:764
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
entry_SYSCALL_64_after_hwframe+0x44/0xa9

RIP: 0033:0x45ca59
Code: Bad RIP value.
RSP: 002b:00007fc044048c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000501e40 RCX: 000000000045ca59

RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003

RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a2b R14: 00000000004cd0f1 R15: 00007fc0440496d4

Memory state around the buggy address:

ffffc90005f1cf00: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90005f1cf80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
>ffffc90005f1d000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
^
ffffc90005f1d080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90005f1d100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================


Tested on:

commit: 472fd78c netlink: avoid interrupting critical section
git tree: https://github.com/congwang/linux.git net
console output: https://syzkaller.appspot.com/x/log.txt?x=10654a55100000

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger crash:

Reported-and-tested-by: syzbot+80cad1...@syzkaller.appspotmail.com

Tested on:

commit: 152c6a4d genetlink: get rid of family->attrbuf

git tree: https://github.com/congwang/linux.git net

kernel config: https://syzkaller.appspot.com/x/.config?x=bf3aec367b9ab569

dashboard link: https://syzkaller.appspot.com/bug?extid=80cad1e3cb4c41cde6ff
compiler: gcc (GCC) 10.1.0-syz 20200507

Note: testing is done by a robot and is best-effort only.