syzbot

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BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:131 [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:131 [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/0x240 net/core/datagram.c:535
 skb_copy_datagram_msg include/linux/skbuff.h:4218 [inline]
 netlink_recvmsg+0x4bb/0xfe0 net/netlink/af_netlink.c:1951
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x2d9/0x380 net/socket.c:1100
 __sys_recvfrom+0x282/0x550 net/socket.c:2256
 __do_sys_recvfrom net/socket.c:2271 [inline]
 __se_sys_recvfrom net/socket.c:2267 [inline]
 __x64_sys_recvfrom+0x130/0x200 net/socket.c:2267
 x64_sys_call+0x3784/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:46
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 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:4508 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_node_track_caller_noprof+0x4f6/0x1750 mm/slub.c:5327
 kmalloc_reserve net/core/skbuff.c:635 [inline]
 __alloc_skb+0x90d/0x1190 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 netlink_dump+0x248/0x1800 net/netlink/af_netlink.c:2290
 __netlink_dump_start+0x716/0xd60 net/netlink/af_netlink.c:2440
 netlink_dump_start include/linux/netlink.h:341 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6856 [inline]
 rtnetlink_rcv_msg+0x1262/0x14b0 net/core/rtnetlink.c:6923
 netlink_rcv_skb+0x54d/0x680 net/netlink/af_netlink.c:2550
 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6985
 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+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 32-35 of 88 are uninitialized
Memory access of size 88 starts at ffff888017c57000
Data copied to user address 00007f9d26594000

CPU: 0 UID: 0 PID: 12164 Comm: syz.6.1561 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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