================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff88e1b288 of 24 bytes by task 15736 on cpu 1: vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878 vscnprintf+0x41/0x90 lib/vsprintf.c:2991 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216 vprintk_store+0x599/0x860 kernel/printk/printk.c:2336 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 __ext4_error+0x248/0x320 fs/ext4/super.c:813 ext4_orphan_get+0x189/0x430 fs/ext4/ialloc.c:1395 ext4_orphan_cleanup+0x5fa/0xa00 fs/ext4/orphan.c:467 __ext4_fill_super fs/ext4/super.c:5609 [inline] ext4_fill_super+0x3260/0x35d0 fs/ext4/super.c:5728 get_tree_bdev_flags+0x291/0x300 fs/super.c:1692 get_tree_bdev+0x1f/0x30 fs/super.c:1715 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5760 vfs_get_tree+0x54/0x1d0 fs/super.c:1815 do_new_mount+0x207/0x5e0 fs/namespace.c:3808 path_mount+0x4a4/0xb20 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166 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 0xffffffff88e1b298 of 8 bytes by task 15744 on cpu 0: data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline] data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:679 data_alloc+0xbf/0x2b0 kernel/printk/printk_ringbuffer.c:1054 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline] show_trace_log_lvl+0x4e3/0x560 arch/x86/kernel/dumpstack.c:282 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0xe8/0x140 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+0x265/0x280 lib/fault-inject.c:174 should_failslab+0x8c/0xb0 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4144 [inline] slab_alloc_node mm/slub.c:4220 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0xa5/0x3e0 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] genl_family_rcv_msg_attrs_parse+0x75/0x190 net/netlink/genetlink.c:940 genl_family_rcv_msg_doit+0x48/0x1b0 net/netlink/genetlink.c:1093 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x422/0x460 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x145/0x180 net/socket.c:729 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2614 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2703 x64_sys_call+0x191e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:47 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: 0x00000000fffffa69 -> 0x6f6c206563697665 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 15744 Comm: syz.3.3353 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ================================================================== genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x145/0x180 net/socket.c:729 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2614 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2703 x64_sys_call+0x191e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:47 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 RIP: 0033:0x7f2b0cf1ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2b0b97f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2b0d155fa0 RCX: 00007f2b0cf1ebe9 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f2b0b97f090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f2b0d156038 R14: 00007f2b0d155fa0 R15: 00007fffd9764758