================================================================== BUG: KCSAN: data-race in _prb_read_valid / prb_reserve write to 0xffffffff876ef168 of 8 bytes by task 6989 on cpu 0: prb_reserve+0x745/0xa70 kernel/printk/printk_ringbuffer.c:1538 log_store kernel/printk/printk.c:506 [inline] log_output kernel/printk/printk.c:1935 [inline] vprintk_store+0x3ce/0x630 kernel/printk/printk.c:1986 vprintk_emit+0xf4/0x490 kernel/printk/printk.c:2011 vprintk_default+0x22/0x30 kernel/printk/printk.c:2045 vprintk_func+0x13b/0x140 kernel/printk/printk_safe.c:393 printk+0x62/0x82 kernel/printk/printk.c:2076 batadv_check_known_mac_addr+0x161/0x190 net/batman-adv/hard-interface.c:518 batadv_hard_if_event+0x407/0xc70 net/batman-adv/hard-interface.c:1064 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2033 [inline] call_netdevice_notifiers_extack net/core/dev.c:2045 [inline] call_netdevice_notifiers net/core/dev.c:2059 [inline] dev_set_mac_address+0x1cd/0x270 net/core/dev.c:8609 do_setlink+0x458/0x2220 net/core/rtnetlink.c:2661 __rtnl_newlink net/core/rtnetlink.c:3374 [inline] rtnl_newlink+0xe62/0x1340 net/core/rtnetlink.c:3500 rtnetlink_rcv_msg+0x71b/0x7b0 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2470 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5581 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x5e2/0x6b0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x6d8/0x7a0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] __sys_sendto+0x2ae/0x380 net/socket.c:1992 __do_sys_sendto net/socket.c:2004 [inline] __se_sys_sendto net/socket.c:2000 [inline] __x64_sys_sendto+0x74/0x90 net/socket.c:2000 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffffffff876ef168 of 8 bytes by task 8385 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:480 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1753 [inline] prb_read kernel/printk/printk_ringbuffer.c:1801 [inline] _prb_read_valid+0x1c9/0x8f0 kernel/printk/printk_ringbuffer.c:1881 prb_read_valid+0x39/0x60 kernel/printk/printk_ringbuffer.c:1930 do_syslog+0xf12/0x15d0 kernel/printk/printk.c:1611 kmsg_read+0x7a/0xa0 fs/proc/kmsg.c:40 pde_read fs/proc/inode.c:306 [inline] proc_reg_read+0xde/0x1a0 fs/proc/inode.c:316 vfs_read+0x16d/0x5f0 fs/read_write.c:479 ksys_read+0xce/0x180 fs/read_write.c:615 __do_sys_read fs/read_write.c:625 [inline] __se_sys_read fs/read_write.c:623 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:623 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 8385 Comm: in:imklog Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================