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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff867143c0 of 8 bytes by task 28527 on cpu 1:
 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
 batadv_check_known_mac_addr+0x147/0x180 net/batman-adv/hard-interface.c:526
 batadv_hard_if_event+0x4b9/0xfb0 net/batman-adv/hard-interface.c:998
 notifier_call_chain kernel/notifier.c:85 [inline]
 raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:453
 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:1996
 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
 call_netdevice_notifiers net/core/dev.c:2048 [inline]
 dev_set_mac_address+0x1ff/0x260 net/core/dev.c:9212
 dev_set_mac_address_user+0x31/0x50 net/core/dev.c:9226
 do_setlink+0x3ec/0x22c0 net/core/rtnetlink.c:3064
 rtnl_changelink net/core/rtnetlink.c:3723 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3875 [inline]
 rtnl_newlink+0xde9/0x1250 net/core/rtnetlink.c:4012
 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_sendto+0x1a8/0x230 net/socket.c:2197
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0x78/0x90 net/socket.c:2200
 x64_sys_call+0x29fa/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:45
 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 0xffffffff867143c0 of 8 bytes by task 28669 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1ec/0xba0 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 __console_flush_and_unlock kernel/printk/printk.c:3288 [inline]
 console_unlock+0x175/0x330 kernel/printk/printk.c:3309
 con_install+0x28d/0x2d0 drivers/tty/vt/vt.c:3547
 tty_driver_install_tty drivers/tty/tty_io.c:1304 [inline]
 tty_init_dev+0x7b/0x320 drivers/tty/tty_io.c:1416
 tty_open_by_driver drivers/tty/tty_io.c:2082 [inline]
 tty_open+0x6c7/0xb00 drivers/tty/tty_io.c:2129
 chrdev_open+0x2f9/0x370 fs/char_dev.c:414
 do_dentry_open+0x621/0xa20 fs/open.c:945
 vfs_open+0x38/0x1f0 fs/open.c:1075
 do_open fs/namei.c:3828 [inline]
 path_openat+0x1ac2/0x1fa0 fs/namei.c:3987
 do_filp_open+0x107/0x230 fs/namei.c:4014
 do_sys_openat2+0xab/0x120 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1428
 x64_sys_call+0x2b30/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0x000000000000f750 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 28669 Comm: syz.6.36663 Not tainted 6.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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