KMSAN: uninit-value in __tipc_nl_compat_dumpit (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f0d5ec90 kmsan: apply __no_sanitize_memory to dotraplinkag..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1206d73d100000
kernel config: https://syzkaller.appspot.com/x/.config?x=86e4f8af239686c6
dashboard link: https://syzkaller.appspot.com/bug?extid=0e7181deafa7e0b79923
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15a6948f100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144e2047100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0e7181...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in __nlmsg_parse include/net/netlink.h:661 [inline]
BUG: KMSAN: uninit-value in nlmsg_parse_deprecated include/net/netlink.h:706 [inline]
BUG: KMSAN: uninit-value in __tipc_nl_compat_dumpit+0x583/0x1290 net/tipc/netlink_compat.c:215
CPU: 0 PID: 8825 Comm: syz-executor230 Not tainted 5.7.0-rc4-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+0x1c9/0x220 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
__nlmsg_parse include/net/netlink.h:661 [inline]
nlmsg_parse_deprecated include/net/netlink.h:706 [inline]
__tipc_nl_compat_dumpit+0x583/0x1290 net/tipc/netlink_compat.c:215
tipc_nl_compat_dumpit+0x761/0x910 net/tipc/netlink_compat.c:308
tipc_nl_compat_handle net/tipc/netlink_compat.c:1272 [inline]
tipc_nl_compat_recv+0x1382/0x2940 net/tipc/netlink_compat.c:1311
genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
genl_rcv_msg+0x20dc/0x2480 net/netlink/genetlink.c:735
netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469
genl_rcv+0x63/0x80 net/netlink/genetlink.c:746
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg net/socket.c:672 [inline]
____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362
___sys_sendmsg net/socket.c:2416 [inline]
__sys_sendmsg+0x623/0x750 net/socket.c:2449
__do_sys_sendmsg net/socket.c:2458 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2456
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456
do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x444219
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 1b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffded8626b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444219
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0
R10: 0000000000001900 R11: 0000000000000246 R12: 0000000000401ec0
R13: 0000000000401f50 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
slab_alloc_node mm/slub.c:2802 [inline]
__kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436
__kmalloc_reserve net/core/skbuff.c:142 [inline]
__alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
alloc_skb include/linux/skbuff.h:1083 [inline]
nlmsg_new include/net/netlink.h:888 [inline]
tipc_nl_compat_dumpit+0x6e4/0x910 net/tipc/netlink_compat.c:301
tipc_nl_compat_handle net/tipc/netlink_compat.c:1272 [inline]
tipc_nl_compat_recv+0x1382/0x2940 net/tipc/netlink_compat.c:1311
genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
genl_rcv_msg+0x20dc/0x2480 net/netlink/genetlink.c:735
netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469
genl_rcv+0x63/0x80 net/netlink/genetlink.c:746
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg net/socket.c:672 [inline]
____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362
___sys_sendmsg net/socket.c:2416 [inline]
__sys_sendmsg+0x623/0x750 net/socket.c:2449
__do_sys_sendmsg net/socket.c:2458 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2456
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456
do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

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https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Cong Wang]

#syz test: https://github.com/congwang/linux.git net

[syzbot]

> #syz test: https://github.com/congwang/linux.git net

I see the command but can't find the corresponding bug.
Please resend the email to syzbo...@syzkaller.appspotmail.com address
that is the sender of the bug report (also present in the Reported-by tag).

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[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+0e7181...@syzkaller.appspotmail.com

Tested on:

commit: ce8056d1 wip: changed copy_from_user where instrumented

git tree: https://github.com/google/kmsan.git master

kernel config: https://syzkaller.appspot.com/x/.config?x=c127b529776787a2

dashboard link: https://syzkaller.appspot.com/bug?extid=0e7181deafa7e0b79923
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

patch: https://syzkaller.appspot.com/x/patch.diff?x=10f77891900000

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

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KMSAN: uninit-value in __nla_validate_parse

=====================================================
BUG: KMSAN: uninit-value in nla_ok include/net/netlink.h:1146 [inline]
BUG: KMSAN: uninit-value in __nla_validate_parse+0x4ea/0x36e0 lib/nlattr.c:521
CPU: 0 PID: 9893 Comm: syz-executor.2 Not tainted 5.8.0-rc5-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+0x1df/0x240 lib/dump_stack.c:118

kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215

nla_ok include/net/netlink.h:1146 [inline]
__nla_validate_parse+0x4ea/0x36e0 lib/nlattr.c:521
__nla_parse+0x141/0x150 lib/nlattr.c:630
__nlmsg_parse include/net/netlink.h:718 [inline]
nlmsg_parse_deprecated include/net/netlink.h:758 [inline]
__tipc_nl_compat_dumpit+0x6b0/0x1290 net/tipc/netlink_compat.c:215
tipc_nl_compat_dumpit+0x8bb/0xb30 net/tipc/netlink_compat.c:321
tipc_nl_compat_handle net/tipc/netlink_compat.c:1285 [inline]
tipc_nl_compat_recv+0x1382/0x2940 net/tipc/netlink_compat.c:1324
genl_family_rcv_msg_doit net/netlink/genetlink.c:669 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:714 [inline]
genl_rcv_msg+0x1592/0x1740 net/netlink/genetlink.c:731
netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469
genl_rcv+0x63/0x80 net/netlink/genetlink.c:742

netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg net/socket.c:672 [inline]

____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
___sys_sendmsg net/socket.c:2406 [inline]
__sys_sendmsg+0x623/0x750 net/socket.c:2439
__do_sys_sendmsg net/socket.c:2448 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2446
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446
do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c429
Code: Bad RIP value.
RSP: 002b:00007f84624b8c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002b3c0 RCX: 000000000045c429
RDX: 0000000000000804 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffe27b3896f R14: 00007f84624b99c0 R15: 000000000078bf0c

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80

slab_alloc_node mm/slub.c:2839 [inline]
__kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4478

__kmalloc_reserve net/core/skbuff.c:142 [inline]
__alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
alloc_skb include/linux/skbuff.h:1083 [inline]

nlmsg_new include/net/netlink.h:940 [inline]
tipc_nl_compat_dumpit+0x709/0xb30 net/tipc/netlink_compat.c:304
tipc_nl_compat_handle net/tipc/netlink_compat.c:1285 [inline]
tipc_nl_compat_recv+0x1382/0x2940 net/tipc/netlink_compat.c:1324
genl_family_rcv_msg_doit net/netlink/genetlink.c:669 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:714 [inline]
genl_rcv_msg+0x1592/0x1740 net/netlink/genetlink.c:731
netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469
genl_rcv+0x63/0x80 net/netlink/genetlink.c:742

netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg net/socket.c:672 [inline]

____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
___sys_sendmsg net/socket.c:2406 [inline]
__sys_sendmsg+0x623/0x750 net/socket.c:2439
__do_sys_sendmsg net/socket.c:2448 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2446
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446
do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================

Tested on:

commit: ce8056d1 wip: changed copy_from_user where instrumented
git tree: https://github.com/google/kmsan.git master

console output: https://syzkaller.appspot.com/x/log.txt?x=13782d4a900000

kernel config: https://syzkaller.appspot.com/x/.config?x=c127b529776787a2
dashboard link: https://syzkaller.appspot.com/bug?extid=0e7181deafa7e0b79923
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

patch: https://syzkaller.appspot.com/x/patch.diff?x=1428125e900000

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+0e7181...@syzkaller.appspotmail.com

Tested on:

commit: ce8056d1 wip: changed copy_from_user where instrumented
git tree: https://github.com/google/kmsan.git master

kernel config: https://syzkaller.appspot.com/x/.config?x=c127b529776787a2
dashboard link: https://syzkaller.appspot.com/bug?extid=0e7181deafa7e0b79923
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

patch: https://syzkaller.appspot.com/x/patch.diff?x=16b29486900000

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+0e7181...@syzkaller.appspotmail.com

Tested on:

commit: ce8056d1 wip: changed copy_from_user where instrumented
git tree: https://github.com/google/kmsan.git master
kernel config: https://syzkaller.appspot.com/x/.config?x=c127b529776787a2
dashboard link: https://syzkaller.appspot.com/bug?extid=0e7181deafa7e0b79923
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

patch: https://syzkaller.appspot.com/x/patch.diff?x=126510ce900000