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BUG: KCSAN: data-race in serial8250_do_startup / serial8250_handle_irq

write to 0xffffffff88eb0ae6 of 1 bytes by task 15366 on cpu 1:
 serial8250_do_startup+0x165e/0x1eb0 drivers/tty/serial/8250/8250_port.c:2460
 serial8250_startup+0x41/0x50 drivers/tty/serial/8250/8250_port.c:2482
 uart_port_startup drivers/tty/serial/serial_core.c:324 [inline]
 uart_startup+0x468/0x8e0 drivers/tty/serial/serial_core.c:368
 uart_port_activate+0x67/0xc0 drivers/tty/serial/serial_core.c:1993
 tty_port_open+0x148/0x1d0 drivers/tty/tty_port.c:764
 uart_open+0x30/0x40 drivers/tty/serial/serial_core.c:1973
 tty_open+0x3d1/0xaf0 drivers/tty/tty_io.c:2137
 chrdev_open+0x2eb/0x3a0 fs/char_dev.c:414
 do_dentry_open+0x646/0xa20 fs/open.c:964
 vfs_open+0x37/0x1e0 fs/open.c:1094
 do_open fs/namei.c:3896 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4055
 do_filp_open+0x109/0x230 fs/namei.c:4082
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x1af/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88eb0ae6 of 1 bytes by interrupt on cpu 0:
 serial8250_handle_irq+0x3f9/0x660 drivers/tty/serial/8250/8250_port.c:1944
 serial8250_default_handle_irq+0x8e/0x120 drivers/tty/serial/8250/8250_port.c:1966
 serial8250_interrupt+0x60/0x110 drivers/tty/serial/8250/8250_core.c:86
 __handle_irq_event_percpu+0x93/0x440 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:210
 handle_edge_irq+0x188/0x4f0 kernel/irq/chip.c:797
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:254 [inline]
 call_irq_handler arch/x86/kernel/irq.c:266 [inline]
 __common_interrupt+0x63/0x100 arch/x86/kernel/irq.c:292
 common_interrupt+0x7e/0x90 arch/x86/kernel/irq.c:285
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 kcsan_setup_watchpoint+0x415/0x430 kernel/kcsan/core.c:705
 should_fail_ex+0x30/0x280 lib/fault-inject.c:146
 should_failslab+0x8c/0xb0 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4101 [inline]
 slab_alloc_node mm/slub.c:4177 [inline]
 kmem_cache_alloc_noprof+0x50/0x310 mm/slub.c:4204
 __kernfs_new_node+0x6d/0x350 fs/kernfs/dir.c:637
 kernfs_new_node+0xd0/0x140 fs/kernfs/dir.c:713
 __kernfs_create_file+0x4b/0x180 fs/kernfs/file.c:1039
 sysfs_add_file_mode_ns+0x132/0x1c0 fs/sysfs/file.c:319
 create_files fs/sysfs/group.c:76 [inline]
 internal_create_group+0x441/0x9e0 fs/sysfs/group.c:183
 internal_create_groups fs/sysfs/group.c:223 [inline]
 sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:249
 device_add_groups drivers/base/core.c:2839 [inline]
 device_add_attrs+0xf4/0x3e0 drivers/base/core.c:2914
 device_add+0x37a/0x770 drivers/base/core.c:3646
 netdev_register_kobject+0xe8/0x210 net/core/net-sysfs.c:2336
 register_netdevice+0x931/0xf00 net/core/dev.c:11105
 macvlan_common_newlink+0x9f0/0xbb0 drivers/net/macvlan.c:1540
 macvlan_newlink+0x25/0x30 drivers/net/macvlan.c:1576
 rtnl_newlink_create+0x1bc/0x620 net/core/rtnetlink.c:3823
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0xf29/0x12d0 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x5fe/0x6d0 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2534
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6971
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x59e/0x670 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x145/0x180 net/socket.c:727
 __sys_sendto+0x268/0x330 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0x76/0x90 net/socket.c:2183
 x64_sys_call+0x2eb6/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15287 Comm: syz-executor Not tainted 6.16.0-rc4-syzkaller-00049-gb4911fb0b060 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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