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] __kmalloc_cache_noprof+0x4c/0x320 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] alloc_name mm/memfd.c:400 [inline] __do_sys_memfd_create mm/memfd.c:471 [inline] __se_sys_memfd_create+0x1cc/0x590 mm/memfd.c:459 __x64_sys_memfd_create+0x31/0x40 mm/memfd.c:459 x64_sys_call+0x122f/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:320 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 ================================================================== BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff8688a548 of 8 bytes by task 18555 on cpu 1: data_alloc+0x271/0x2b0 kernel/printk/printk_ringbuffer.c:1095 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 validate_nla lib/nlattr.c:414 [inline] __nla_validate_parse+0x1227/0x1d00 lib/nlattr.c:635 __nla_parse+0x40/0x60 lib/nlattr.c:732 __nlmsg_parse include/net/netlink.h:787 [inline] genl_family_rcv_msg_attrs_parse+0x13b/0x190 net/netlink/genetlink.c:945 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+0x5a5/0x680 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x145/0x180 net/socket.c:727 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2566 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2655 x64_sys_call+0x2999/0x2fb0 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 read to 0xffffffff8688a548 of 16 bytes by task 18557 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:482 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline] prb_read kernel/printk/printk_ringbuffer.c:1922 [inline] _prb_read_valid+0x1bc/0x920 kernel/printk/printk_ringbuffer.c:2113 desc_update_last_finalized kernel/printk/printk_ringbuffer.c:1515 [inline] prb_final_commit+0x136/0x1e0 kernel/printk/printk_ringbuffer.c:1782 vprintk_store+0x741/0x860 kernel/printk/printk.c:2352 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:4101 [inline] slab_alloc_node mm/slub.c:4177 [inline] __kmalloc_cache_noprof+0x4c/0x320 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] alloc_name mm/memfd.c:400 [inline] __do_sys_memfd_create mm/memfd.c:471 [inline] __se_sys_memfd_create+0x1cc/0x590 mm/memfd.c:459 __x64_sys_memfd_create+0x31/0x40 mm/memfd.c:459 x64_sys_call+0x122f/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:320 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 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 18557 Comm: syz.2.15932 Tainted: G W 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ================================================================== entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc654d2e929 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:00007fc653396e18 EFLAGS: 00000202 ORIG_RAX: 000000000000013f RAX: ffffffffffffffda RBX: 000000000000053e RCX: 00007fc654d2e929 RDX: 00007fc653396ef0 RSI: 0000000000000000 RDI: 00007fc654db14cc RBP: 0000200000000940 R08: 00007fc653396bb7 R09: 00007fc653396e40 R10: 000000000000000a R11: 0000000000000202 R12: 0000200000000000 R13: 00007fc653396ef0 R14: 00007fc653396eb0 R15: 00002000000003c0