syzbot

BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff893a2618 of 8 bytes by task 3302 on cpu 0:
 data_alloc+0x240/0x380 kernel/printk/printk_ringbuffer.c:1116
 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 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
 dump_header+0x80/0x240 mm/oom_kill.c:464
 oom_kill_process+0x295/0x350 mm/oom_kill.c:1031
 out_of_memory+0x981/0xbc0 mm/oom_kill.c:1169
 mem_cgroup_out_of_memory mm/memcontrol.c:1907 [inline]
 mem_cgroup_oom mm/memcontrol.c:1930 [inline]
 try_charge_memcg+0x621/0xa00 mm/memcontrol.c:2697
 charge_memcg+0x6d/0x120 mm/memcontrol.c:5126
 __mem_cgroup_charge+0x28/0xb0 mm/memcontrol.c:5143
 mem_cgroup_charge include/linux/memcontrol.h:641 [inline]
 filemap_add_folio+0x110/0x350 mm/filemap.c:959
 __filemap_get_folio_mpol+0x32e/0x840 mm/filemap.c:2022
 __filemap_get_folio include/linux/pagemap.h:761 [inline]
 filemap_fault+0x458/0xb60 mm/filemap.c:3592
 __do_fault mm/memory.c:5425 [inline]
 do_read_fault mm/memory.c:5860 [inline]
 do_fault mm/memory.c:5994 [inline]
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0x167a/0x2da0 mm/memory.c:6686
 do_user_addr_fault+0x634/0x1060 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595

read to 0xffffffff893a2618 of 8 bytes by task 29 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x104/0x440 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x111/0x380 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 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
 kauditd_printk_skb kernel/audit.c:588 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:623
 kauditd_send_queue+0x275/0x2d0 kernel/audit.c:808
 kauditd_thread+0x439/0x660 kernel/audit.c:932
 kthread+0x221/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x3fffffffffffe452 -> 0x3fffffffffffeddc

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29 Comm: kauditd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
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