KMSAN: uninit-value in dgram_sendmsg

KMSAN: uninit-value in dgram_sendmsg

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    29ad81a1 arch/x86: add missing include to sparsemem.h
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=13b86466d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8e3b38ca92283e
dashboard link: https://syzkaller.appspot.com/bug?extid=a209a964d48b219587cc
compiler:       Debian clang version 11.0.1-2
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a209a964d48b219587cc@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in ieee802154_addr_from_sa include/net/ieee802154_netdev.h:174 [inline]
BUG: KMSAN: uninit-value in dgram_sendmsg+0x14cb/0x15c0 net/ieee802154/socket.c:660
CPU: 0 PID: 14314 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 ieee802154_addr_from_sa include/net/ieee802154_netdev.h:174 [inline]
 dgram_sendmsg+0x14cb/0x15c0 net/ieee802154/socket.c:660
 ieee802154_sock_sendmsg+0xec/0x130 net/ieee802154/socket.c:97
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x714/0x830 net/socket.c:2432
 __compat_sys_sendmsg net/compat.c:347 [inline]
 __do_compat_sys_sendmsg net/compat.c:354 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351
 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline]
 __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:141
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:166
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:209
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fcc549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f55c65fc EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000380
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Local variable ----address.i@__sys_sendmsg created at:
 ___sys_sendmsg net/socket.c:2389 [inline]
 __sys_sendmsg+0x30e/0x830 net/socket.c:2432
 ___sys_sendmsg net/socket.c:2389 [inline]
 __sys_sendmsg+0x30e/0x830 net/socket.c:2432
=====================================================


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