__dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 lib/dump_stack.c:120 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff86e66f68 of 8 bytes by task 11463 on cpu 0: data_alloc+0x308/0x380 kernel/printk/printk_ringbuffer.c:1130 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 __netdev_printk+0x310/0x370 net/core/dev.c:13209 netdev_info+0xa6/0xd0 net/core/dev.c:13256 team_port_add drivers/net/team/team_core.c:1383 [inline] team_add_slave+0x14b0/0x1820 drivers/net/team/team_core.c:2113 do_set_master+0x37b/0x450 net/core/rtnetlink.c:3076 do_setlink+0x976/0x2860 net/core/rtnetlink.c:3278 rtnl_changelink net/core/rtnetlink.c:3910 [inline] __rtnl_newlink net/core/rtnetlink.c:4081 [inline] rtnl_newlink+0x115a/0x1510 net/core/rtnetlink.c:4220 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:7137 netlink_rcv_skb+0x11e/0x220 net/netlink/af_netlink.c:2575 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7164 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline] netlink_unicast+0x5a9/0x680 net/netlink/af_netlink.c:1364 netlink_sendmsg+0x5be/0x6f0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x411/0x470 net/socket.c:2281 __do_sys_sendto net/socket.c:2288 [inline] __se_sys_sendto net/socket.c:2284 [inline] __x64_sys_sendto+0x76/0x90 net/socket.c:2284 x64_sys_call+0x200c/0x2550 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86e66f68 of 8 bytes by task 11530 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:496 [inline] desc_push_tail kernel/printk/printk_ringbuffer.c:792 [inline] desc_reserve kernel/printk/printk_ringbuffer.c:938 [inline] prb_reserve+0x21a/0xaf0 kernel/printk/printk_ringbuffer.c:1677 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline] __show_trace_log_lvl+0x460/0x560 arch/x86/kernel/dumpstack.c:282 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x262/0x280 lib/fault-inject.c:174 should_fail+0xb/0x20 lib/fault-inject.c:184 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:35 copy_from_user_iter lib/iov_iter.c:50 [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_from_iter lib/iov_iter.c:261 [inline] _copy_from_iter+0xcc/0xe70 lib/iov_iter.c:272 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] memcpy_from_msg include/linux/skbuff.h:4311 [inline] netlink_sendmsg+0x4a4/0x6f0 net/netlink/af_netlink.c:1904 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] sock_write_iter+0x2c5/0x2f0 net/socket.c:1266 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x57f/0x9a0 fs/read_write.c:687 ksys_write+0xdc/0x1a0 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __x64_sys_write+0x40/0x50 fs/read_write.c:747 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0xfffffffffffc7a10 -> 0x0000000000068370 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 11530 Comm: syz.1.1299 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 ================================================================== dump_stack+0x15/0x1b lib/dump_stack.c:129 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x262/0x280 lib/fault-inject.c:174 should_fail+0xb/0x20 lib/fault-inject.c:184 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:35 copy_from_user_iter lib/iov_iter.c:50 [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_from_iter lib/iov_iter.c:261 [inline] _copy_from_iter+0xcc/0xe70 lib/iov_iter.c:272 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] memcpy_from_msg include/linux/skbuff.h:4311 [inline] netlink_sendmsg+0x4a4/0x6f0 net/netlink/af_netlink.c:1904 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] sock_write_iter+0x2c5/0x2f0 net/socket.c:1266 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x57f/0x9a0 fs/read_write.c:687 ksys_write+0xdc/0x1a0 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __x64_sys_write+0x40/0x50 fs/read_write.c:747 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f21c223e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f21c0c97028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f21c24c5fa0 RCX: 00007f21c223e159 RDX: 000000000000fe33 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f21c0c97090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f21c24c6038 R14: 00007f21c24c5fa0 R15: 00007fff2ca7ebd8