netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. ===================================================== 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:29 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185 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:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185 copy_to_iter include/linux/uio.h:196 [inline] simple_copy_to_iter net/core/datagram.c:532 [inline] __skb_datagram_iter+0x185/0x1000 net/core/datagram.c:420 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546 skb_copy_datagram_msg include/linux/skbuff.h:4055 [inline] netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1962 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x2c4/0x340 net/socket.c:1068 ____sys_recvmsg+0x18a/0x620 net/socket.c:2803 ___sys_recvmsg+0x223/0x840 net/socket.c:2845 do_recvmmsg+0x627/0xfd0 net/socket.c:2931 __sys_recvmmsg+0x10a/0x430 net/socket.c:3018 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline] __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline] __ia32_compat_sys_recvmmsg_time32+0xf5/0x180 net/compat.c:414 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xba/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:346 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:384 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc_node_track_caller+0x747/0x1060 mm/slub.c:3986 kmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:599 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] netlink_dump+0x28e/0x15b0 net/netlink/af_netlink.c:2235 __netlink_dump_start+0xb3a/0xce0 net/netlink/af_netlink.c:2386 netlink_dump_start include/linux/netlink.h:340 [inline] rtnetlink_rcv_msg+0x1445/0x1900 net/core/rtnetlink.c:6551 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 ____sys_sendmsg+0x877/0xb60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg+0x225/0x3c0 net/socket.c:2667 __compat_sys_sendmsg net/compat.c:346 [inline] __do_compat_sys_sendmsg net/compat.c:353 [inline] __se_compat_sys_sendmsg net/compat.c:350 [inline] __ia32_compat_sys_sendmsg+0x9d/0xe0 net/compat.c:350 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xba/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:346 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:384 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 Bytes 32-35 of 44 are uninitialized Memory access of size 44 starts at ffff8880253f7000 Data copied to user address 0000000020000080 CPU: 0 PID: 8252 Comm: syz-executor.1 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 =====================================================