syzbot

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BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]
BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:30 [inline]
BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:330 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0xef3/0x3400 lib/iov_iter.c:197
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 copy_to_user_iter lib/iov_iter.c:24 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 _copy_to_iter+0xef3/0x3400 lib/iov_iter.c:197
 copy_to_iter include/linux/uio.h:220 [inline]
 simple_copy_to_iter net/core/datagram.c:521 [inline]
 __skb_datagram_iter+0x18f/0x12b0 net/core/datagram.c:402
 skb_copy_datagram_iter+0x5b/0x1e0 net/core/datagram.c:535
 skb_copy_datagram_msg include/linux/skbuff.h:4217 [inline]
 packet_recvmsg+0xe34/0x2510 net/packet/af_packet.c:3472
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x2d9/0x380 net/socket.c:1100
 sock_read_iter+0x2c8/0x360 net/socket.c:1170
 do_iter_readv_writev+0x9e0/0xc10 fs/read_write.c:-1
 vfs_readv+0x34a/0xf30 fs/read_write.c:1018
 do_readv+0x235/0x5d0 fs/read_write.c:1080
 __do_sys_readv fs/read_write.c:1165 [inline]
 __se_sys_readv fs/read_write.c:1162 [inline]
 __x64_sys_readv+0x99/0xf0 fs/read_write.c:1162
 x64_sys_call+0x3083/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:20
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4960 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_node_noprof+0x9de/0x1780 mm/slub.c:5315
 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586
 __alloc_skb+0x805/0x1030 net/core/skbuff.c:690
 alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
 tipc_buf_acquire+0x4c/0x230 net/tipc/msg.c:72
 tipc_disc_create+0x12f/0x870 net/tipc/discover.c:359
 tipc_enable_bearer net/tipc/bearer.c:348 [inline]
 __tipc_nl_bearer_enable+0x1f61/0x2a00 net/tipc/bearer.c:1047
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:371 [inline]
 tipc_nl_compat_doit+0x67b/0xa10 net/tipc/netlink_compat.c:393
 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline]
 tipc_nl_compat_recv+0xfce/0x1630 net/tipc/netlink_compat.c:1321
 genl_family_rcv_msg_doit+0x338/0x3f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0xac5/0xc00 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x54d/0x680 net/netlink/af_netlink.c:2550
 genl_rcv+0x41/0x60 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x10b2/0x1250 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xfe7/0x1080 net/socket.c:2592
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2681
 x64_sys_call+0x1c60/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 4-5 of 22 are uninitialized
Memory access of size 22 starts at ffff8880795516a4
Data copied to user address 0000200000000140

CPU: 1 UID: 0 PID: 12207 Comm: syz.3.1727 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
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