netlink: 24 bytes leftover after parsing attributes in process `syz.3.10676'. ================================================================== BUG: KCSAN: data-race in _prb_read_valid / prb_reserve write to 0xffffffff86736c28 of 8 bytes by task 1941 on cpu 0: prb_reserve+0x740/0xb60 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2408 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447 vprintk+0x75/0x80 kernel/printk/printk_safe.c:86 _printk+0x7a/0xa0 kernel/printk/printk.c:2457 __ext4_msg+0x18e/0x1a0 fs/ext4/super.c:998 ext4_check_journal_data_mode fs/ext4/super.c:5014 [inline] __ext4_fill_super fs/ext4/super.c:5305 [inline] ext4_fill_super+0x2174/0x3a10 fs/ext4/super.c:5733 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636 get_tree_bdev+0x1f/0x30 fs/super.c:1659 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5765 vfs_get_tree+0x56/0x1e0 fs/super.c:1814 do_new_mount+0x227/0x690 fs/namespace.c:3507 path_mount+0x49b/0xb30 fs/namespace.c:3834 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x27c/0x2d0 fs/namespace.c:4034 __x64_sys_mount+0x67/0x80 fs/namespace.c:4034 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86736c28 of 8 bytes by task 1944 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:486 [inline] prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline] _prb_read_valid+0x3bb/0xba0 kernel/printk/printk_ringbuffer.c:2114 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182 printk_get_next_message+0xd4/0x710 kernel/printk/printk.c:2989 console_emit_next_record kernel/printk/printk.c:3076 [inline] console_flush_all+0x28a/0x770 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xab/0x330 kernel/printk/printk.c:3309 vprintk_emit+0x3f4/0x680 kernel/printk/printk.c:2432 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447 vprintk+0x75/0x80 kernel/printk/printk_safe.c:86 _printk+0x7a/0xa0 kernel/printk/printk.c:2457 __nla_validate_parse+0x1881/0x1e30 lib/nlattr.c:647 __nla_parse+0x40/0x60 lib/nlattr.c:732 nla_parse_nested_deprecated include/net/netlink.h:1342 [inline] rtnl_newlink+0x250/0x1250 net/core/rtnetlink.c:3928 rtnetlink_rcv_msg+0x651/0x710 net/core/rtnetlink.c:6922 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2542 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6949 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x599/0x670 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x5cc/0x6e0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:726 ____sys_sendmsg+0x312/0x410 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x19d/0x230 net/socket.c:2669 __do_sys_sendmsg net/socket.c:2674 [inline] __se_sys_sendmsg net/socket.c:2672 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2672 x64_sys_call+0x2734/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000000003d97 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 1944 Comm: syz.3.10676 Tainted: G W 6.13.0-rc6-syzkaller #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ==================================================================