CPU: 1 PID: 4143 Comm: syz-executor.0 Not tainted 6.1.0-rc7-syzkaller-00200-gc2bf05db6c78-dirty #0
==================================================================
BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff87094ba0 of 8 bytes by task 4142 on cpu 0:
 data_alloc+0x205/0x2b0 kernel/printk/printk_ringbuffer.c:1074
 prb_reserve+0x897/0xbd0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x51c/0xb50 kernel/printk/printk.c:2193
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2249
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2279
 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50
 _printk+0x76/0x96 kernel/printk/printk.c:2289
 pagefault_out_of_memory+0xc8/0xd0 mm/oom_kill.c:1197
 handle_page_fault arch/x86/mm/fault.c:1519 [inline]
 exc_page_fault+0x60/0x160 arch/x86/mm/fault.c:1575
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffffffff87094ba0 of 8 bytes by task 4143 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x10f/0x440 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1046
 prb_reserve+0x897/0xbd0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x51c/0xb50 kernel/printk/printk.c:2193
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2249
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2279
 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50
 _printk+0x76/0x96 kernel/printk/printk.c:2289
 dump_stack_print_info+0xb7/0x130 lib/dump_stack.c:57
 __dump_stack lib/dump_stack.c:87 [inline]
 dump_stack_lvl+0xca/0x122 lib/dump_stack.c:106
 dump_stack+0x11/0x13 lib/dump_stack.c:113
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x218/0x220 lib/fault-inject.c:147
 prepare_alloc_pages mm/page_alloc.c:5330 [inline]
 __alloc_pages+0x10a/0x340 mm/page_alloc.c:5547
 vma_alloc_folio+0x6a0/0x8e0 mm/mempolicy.c:2246
 alloc_page_vma include/linux/gfp.h:284 [inline]
 do_anonymous_page+0x156/0xa10 mm/memory.c:4113
 handle_pte_fault mm/memory.c:4952 [inline]
 __handle_mm_fault mm/memory.c:5096 [inline]
 handle_mm_fault+0x88e/0xa80 mm/memory.c:5217
 do_user_addr_fault+0x4a1/0x980 arch/x86/mm/fault.c:1428
 handle_page_fault arch/x86/mm/fault.c:1519 [inline]
 exc_page_fault+0x60/0x160 arch/x86/mm/fault.c:1575
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0x00000000ffffe403 -> 0x00000000fffff249

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4143 Comm: syz-executor.0 Not tainted 6.1.0-rc7-syzkaller-00200-gc2bf05db6c78-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd6/0x122 lib/dump_stack.c:106
 dump_stack+0x11/0x13 lib/dump_stack.c:113
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x218/0x220 lib/fault-inject.c:147
 prepare_alloc_pages mm/page_alloc.c:5330 [inline]
 __alloc_pages+0x10a/0x340 mm/page_alloc.c:5547
 vma_alloc_folio+0x6a0/0x8e0 mm/mempolicy.c:2246
 alloc_page_vma include/linux/gfp.h:284 [inline]
 do_anonymous_page+0x156/0xa10 mm/memory.c:4113
 handle_pte_fault mm/memory.c:4952 [inline]
 __handle_mm_fault mm/memory.c:5096 [inline]
 handle_mm_fault+0x88e/0xa80 mm/memory.c:5217
 do_user_addr_fault+0x4a1/0x980 arch/x86/mm/fault.c:1428
 handle_page_fault arch/x86/mm/fault.c:1519 [inline]
 exc_page_fault+0x60/0x160 arch/x86/mm/fault.c:1575
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f0940f490c0
Code: e8 e5 fe ff ff 41 89 c7 85 c0 78 40 3d ff 00 00 00 7f 2f 49 8b 45 10 49 3b 45 08 0f 84 19 01 00 00 45 85 ff 74 0c 49 8b 55 00 <44> 88 3c 02 49 8b 45 10 48 83 c0 01 49 89 45 10 eb be 66 0f 1f 44
RSP: 002b:00007f094031e600 EFLAGS: 00010206
RAX: 000000000000b000 RBX: 00007f094031e660 RCX: 0000000000000007
RDX: 00007f0937eff000 RSI: 000000000000001f RDI: 00007f094031e700
RBP: 000000000000004f R08: 0000000000000008 R09: 00000000000000b8
R10: 0000000000000010 R11: 00007f094031e660 R12: 00007f094031e670
R13: 00007f094031e700 R14: 0000000000000001 R15: 0000000000000027
 </TASK>
Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF
loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback.
ext4 filesystem being mounted at /root/syzkaller-testdir350304044/syzkaller.sj9nk0/75/file0 supports timestamps until 2038 (0x7fffffff)