CPU: 1 PID: 21334 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00021-gcf1182944c7c #0 ================================================================== BUG: KCSAN: data-race in data_push_tail / number write to 0xffffffff8710668b of 1 bytes by task 21330 on cpu 0: number+0x7d0/0xa90 lib/vsprintf.c:564 vsnprintf+0xa44/0xe30 lib/vsprintf.c:2890 vscnprintf+0x42/0x80 lib/vsprintf.c:2930 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124 vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2328 br_set_state+0x2e2/0x390 net/bridge/br_stp.c:54 br_make_forwarding+0xbc/0x150 net/bridge/br_stp.c:455 br_port_state_selection+0x115/0x310 br_set_port_state net/bridge/br_netlink.c:924 [inline] br_setport+0xc38/0xc50 net/bridge/br_netlink.c:1014 br_setlink+0x314/0x450 net/bridge/br_netlink.c:1117 rtnl_bridge_setlink+0x34a/0x480 net/core/rtnetlink.c:5216 rtnetlink_rcv_msg+0x80a/0x8c0 net/core/rtnetlink.c:6618 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2543 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6636 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x589/0x660 net/netlink/af_netlink.c:1367 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x1e9/0x270 net/socket.c:2667 __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b read to 0xffffffff87106688 of 8 bytes by task 21334 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline] data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046 prb_reserve+0x897/0xbc0 kernel/printk/printk_ringbuffer.c:1555 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2328 dump_stack_print_info+0xb4/0x120 lib/dump_stack.c:57 __dump_stack lib/dump_stack.c:87 [inline] dump_stack_lvl+0xce/0x130 lib/dump_stack.c:106 dump_stack+0x15/0x20 lib/dump_stack.c:113 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x21f/0x230 lib/fault-inject.c:153 should_fail+0xb/0x10 lib/fault-inject.c:163 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37 _copy_from_user+0x1e/0xd0 lib/usercopy.c:15 copy_from_user include/linux/uaccess.h:183 [inline] copy_msghdr_from_user+0x54/0x2a0 net/socket.c:2514 sendmsg_copy_msghdr net/socket.c:2615 [inline] ___sys_sendmsg net/socket.c:2634 [inline] __sys_sendmsg+0x17d/0x270 net/socket.c:2667 __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b value changed: 0x00000001000058a1 -> 0x0000000100207472 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 21334 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00021-gcf1182944c7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 ================================================================== Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xda/0x130 lib/dump_stack.c:106 dump_stack+0x15/0x20 lib/dump_stack.c:113 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x21f/0x230 lib/fault-inject.c:153 should_fail+0xb/0x10 lib/fault-inject.c:163 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37 _copy_from_user+0x1e/0xd0 lib/usercopy.c:15 copy_from_user include/linux/uaccess.h:183 [inline] copy_msghdr_from_user+0x54/0x2a0 net/socket.c:2514 sendmsg_copy_msghdr net/socket.c:2615 [inline] ___sys_sendmsg net/socket.c:2634 [inline] __sys_sendmsg+0x17d/0x270 net/socket.c:2667 __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fd6b9b64da9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd6b8ee60c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd6b9c92f80 RCX: 00007fd6b9b64da9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007fd6b8ee6120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 000000000000000b R14: 00007fd6b9c92f80 R15: 00007ffd22e77968