Re: [syzbot] [modules?] KMSAN: uninit-value in __request_module (6)

[syzbot <syzbot+1fcd957a82e3a1baa94d@syzkaller.appspotmail.com>]

Hello,

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

=====================================================
BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:636 [inline]
BUG: KMSAN: uninit-value in string+0x3ec/0x5f0 lib/vsprintf.c:717
 string_nocheck lib/vsprintf.c:636 [inline]
 string+0x3ec/0x5f0 lib/vsprintf.c:717
 vsnprintf+0xa5d/0x1960 lib/vsprintf.c:2846
 __request_module+0x252/0x9f0 kernel/module/kmod.c:149
 team_mode_get drivers/net/team/team_core.c:480 [inline]
 team_change_mode drivers/net/team/team_core.c:607 [inline]
 team_mode_option_set+0x437/0x970 drivers/net/team/team_core.c:1401
 team_option_set drivers/net/team/team_core.c:375 [inline]
 team_nl_options_set_doit+0x1339/0x1f90 drivers/net/team/team_core.c:2661
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x1214/0x12c0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2543
 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:733
 ____sys_sendmsg+0x877/0xb60 net/socket.c:2573
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2627
 __sys_sendmsg net/socket.c:2659 [inline]
 __do_sys_sendmsg net/socket.c:2664 [inline]
 __se_sys_sendmsg net/socket.c:2662 [inline]
 __x64_sys_sendmsg+0x212/0x3c0 net/socket.c:2662
 x64_sys_call+0x2ed6/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4121 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_node_noprof+0x907/0xe00 mm/slub.c:4216
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1331 [inline]
 netlink_alloc_large_skb+0x1b4/0x280 net/netlink/af_netlink.c:1196
 netlink_sendmsg+0xa96/0x11e0 net/netlink/af_netlink.c:1867
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:733
 ____sys_sendmsg+0x877/0xb60 net/socket.c:2573
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2627
 __sys_sendmsg net/socket.c:2659 [inline]
 __do_sys_sendmsg net/socket.c:2664 [inline]
 __se_sys_sendmsg net/socket.c:2662 [inline]
 __x64_sys_sendmsg+0x212/0x3c0 net/socket.c:2662
 x64_sys_call+0x2ed6/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 6614 Comm: syz.0.16 Not tainted 6.14.0-rc2-syzkaller-gab68d7eb7b1a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
=====================================================


Tested on:

commit:         ab68d7eb Merge tag 'loongarch-fixes-6.14-1' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122893f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=48f90cac5eea091a
dashboard link: https://syzkaller.appspot.com/bug?extid=1fcd957a82e3a1baa94d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13a721a4580000