inactive_anon 0
active_anon 0
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86e71360 of 8 bytes by task 18152 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
 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_failslab+0x8c/0xb0 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4638 [inline]
 slab_alloc_node mm/slub.c:4974 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_track_caller_noprof+0xd6/0x500 mm/slub.c:5545
 __kmemdup_nul mm/util.c:64 [inline]
 kstrndup+0x7e/0x120 mm/util.c:120
 asymmetric_lookup_restriction+0x7b/0x370 crypto/asymmetric_keys/asymmetric_type.c:520
 keyring_restrict+0xf2/0x280 security/keys/keyring.c:1053
 keyctl_restrict_keyring+0x10a/0x1c0 security/keys/keyctl.c:1772
 __do_sys_keyctl security/keys/keyctl.c:1995 [inline]
 __se_sys_keyctl+0x228/0xb70 security/keys/keyctl.c:1886
 __x64_sys_keyctl+0x67/0x80 security/keys/keyctl.c:1886
 x64_sys_call+0x1fe0/0x2550 arch/x86/include/generated/asm/syscalls_64.h:251
 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 0xffffffff86e71360 of 8 bytes by task 18147 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
 seq_buf_do_printk+0x113/0x1a0 lib/seq_buf.c:126
 mem_cgroup_print_oom_meminfo+0x17d/0x260 mm/memcontrol.c:1874
 dump_header+0xa2/0x240 mm/oom_kill.c:466
 oom_kill_process+0x294/0x420 mm/oom_kill.c:1031
 out_of_memory+0x981/0xbc0 mm/oom_kill.c:1169
 mem_cgroup_out_of_memory mm/memcontrol.c:1952 [inline]
 mem_cgroup_oom mm/memcontrol.c:1975 [inline]
 try_charge_memcg+0x6ba/0xae0 mm/memcontrol.c:2760
 try_charge mm/memcontrol.c:2860 [inline]
 obj_cgroup_charge_pages mm/memcontrol.c:3161 [inline]
 __obj_cgroup_charge+0x120/0x250 mm/memcontrol.c:3539
 __memcg_slab_post_alloc_hook+0x4c4/0x8d0 mm/memcontrol.c:3669
 memcg_slab_post_alloc_hook mm/slub.c:2517 [inline]
 slab_post_alloc_hook mm/slub.c:4702 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_noprof+0x255/0x4d0 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 __register_sysctl_table+0x52/0xbe0 fs/proc/proc_sysctl.c:1378
 register_net_sysctl_sz+0x118/0x190 net/sysctl_net.c:172
 sctp_sysctl_net_register+0x499/0x4f0 net/sctp/sysctl.c:607
 sctp_ctrlsock_init+0xa6/0x140 net/sctp/protocol.c:1451
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:137
 setup_net+0x9f/0x230 net/core/net_namespace.c:443
 copy_net_ns+0x333/0x490 net/core/net_namespace.c:582
 create_new_namespaces+0x1f6/0x420 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x115/0x150 kernel/nsproxy.c:234
 ksys_unshare+0x42b/0x710 kernel/fork.c:3295
 __do_sys_unshare kernel/fork.c:3359 [inline]
 __se_sys_unshare kernel/fork.c:3357 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3357
 x64_sys_call+0x1e33/0x2550 arch/x86/include/generated/asm/syscalls_64.h:273
 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: 0x00000000001b05e8 -> 0x000000000025aea0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 18147 Comm: syz.0.10764 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
inactive_file 0
active_file 0
unevictable 0
hierarchical_memory_limit 98304
hierarchical_memsw_limit 9223372036854771712
total_cache 0
total_rss 0
total_shmem 0
total_mapped_file 0
total_dirty 0
total_writeback 0
total_workingset_refault_anon 0
total_workingset_refault_file 0
total_swap 0
total_swapcached 16384
total_pgpgin 4
total_pgpgout 4
total_pgfault 108
total_pgmajfault 0
total_inactive_anon 0
total_active_anon 0
total_inactive_file 0
total_active_file 0
total_unevictable 0
oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/syz0/test,task_memcg=/syz0/test,task=syz.0.10764,pid=18146,uid=0
Memory cgroup out of memory: Killed process 18146 (syz.0.10764) total-vm:94056kB, anon-rss:1424kB, file-rss:22496kB, shmem-rss:0kB, UID:0 pgtables:128kB oom_score_adj:1000