================================================================== BUG: KCSAN: data-race in data_push_tail / number write to 0xffffffff86fe0420 of 1 bytes by task 6333 on cpu 0: number+0x6fb/0xb60 lib/vsprintf.c:548 vsnprintf+0xb6d/0xed0 lib/vsprintf.c:2872 vscnprintf+0x29/0x80 lib/vsprintf.c:2909 printk_sprint kernel/printk/printk.c:2099 [inline] vprintk_store+0x638/0xbb0 kernel/printk/printk.c:2209 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2256 vprintk_default+0x22/0x30 kernel/printk/printk.c:2283 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50 _printk+0x76/0x97 kernel/printk/printk.c:2293 __show_regs+0x9d/0x330 arch/x86/kernel/process_64.c:85 show_regs_if_on_stack arch/x86/kernel/dumpstack.c:167 [inline] show_trace_log_lvl+0x5b8/0x670 arch/x86/kernel/dumpstack.c:292 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd6/0x122 lib/dump_stack.c:106 dump_stack+0x11/0x1b lib/dump_stack.c:113 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x23c/0x250 lib/fault-inject.c:146 __should_failslab+0x81/0x90 mm/failslab.c:33 should_failslab+0x5/0x20 mm/slab_common.c:1304 slab_pre_alloc_hook mm/slab.h:724 [inline] slab_alloc mm/slab.c:3299 [inline] __kmem_cache_alloc_lru mm/slab.c:3492 [inline] kmem_cache_alloc+0x4f/0x320 mm/slab.c:3512 vm_area_dup kernel/fork.c:464 [inline] dup_mmap+0x40e/0xa60 kernel/fork.c:640 dup_mm+0x7c/0x210 kernel/fork.c:1518 copy_mm kernel/fork.c:1570 [inline] copy_process+0x160e/0x3100 kernel/fork.c:2231 kernel_clone+0x15c/0x6a0 kernel/fork.c:2636 __do_sys_clone3 kernel/fork.c:2911 [inline] __se_sys_clone3 kernel/fork.c:2895 [inline] __x64_sys_clone3+0x1ce/0x210 kernel/fork.c:2895 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffffffff86fe0420 of 8 bytes by task 6351 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline] data_push_tail+0x138/0x470 kernel/printk/printk_ringbuffer.c:675 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1046 prb_reserve+0x931/0xc10 kernel/printk/printk_ringbuffer.c:1555 vprintk_store+0x560/0xbb0 kernel/printk/printk.c:2199 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2256 vprintk_default+0x22/0x30 kernel/printk/printk.c:2283 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50 _printk+0x76/0x97 kernel/printk/printk.c:2293 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x223/0x250 lib/fault-inject.c:146 __should_failslab+0x81/0x90 mm/failslab.c:33 should_failslab+0x5/0x20 mm/slab_common.c:1304 slab_pre_alloc_hook mm/slab.h:724 [inline] slab_alloc mm/slab.c:3299 [inline] __kmem_cache_alloc_lru mm/slab.c:3492 [inline] kmem_cache_alloc+0x4f/0x320 mm/slab.c:3512 anon_vma_chain_alloc mm/rmap.c:137 [inline] anon_vma_clone+0x8d/0x380 mm/rmap.c:283 anon_vma_fork+0x54/0x2b0 mm/rmap.c:346 dup_mmap+0x52b/0xa60 kernel/fork.c:657 dup_mm+0x7c/0x210 kernel/fork.c:1518 copy_mm kernel/fork.c:1570 [inline] copy_process+0x160e/0x3100 kernel/fork.c:2231 kernel_clone+0x15c/0x6a0 kernel/fork.c:2636 __do_sys_clone kernel/fork.c:2753 [inline] __se_sys_clone kernel/fork.c:2737 [inline] __x64_sys_clone+0xc6/0xf0 kernel/fork.c:2737 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000100004cca -> 0x3730303030303030 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 6351 Comm: syz-executor.2 Not tainted 5.17.0-syzkaller-09727-g34af78c4e616-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== CPU: 1 PID: 6351 Comm: syz-executor.2 Not tainted 5.17.0-syzkaller-09727-g34af78c4e616-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd6/0x122 lib/dump_stack.c:106 dump_stack+0x11/0x1b lib/dump_stack.c:113 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x23c/0x250 lib/fault-inject.c:146 __should_failslab+0x81/0x90 mm/failslab.c:33 should_failslab+0x5/0x20 mm/slab_common.c:1304 slab_pre_alloc_hook mm/slab.h:724 [inline] slab_alloc mm/slab.c:3299 [inline] __kmem_cache_alloc_lru mm/slab.c:3492 [inline] kmem_cache_alloc+0x4f/0x320 mm/slab.c:3512 anon_vma_chain_alloc mm/rmap.c:137 [inline] anon_vma_clone+0x8d/0x380 mm/rmap.c:283 anon_vma_fork+0x54/0x2b0 mm/rmap.c:346 dup_mmap+0x52b/0xa60 kernel/fork.c:657 dup_mm+0x7c/0x210 kernel/fork.c:1518 copy_mm kernel/fork.c:1570 [inline] copy_process+0x160e/0x3100 kernel/fork.c:2231 kernel_clone+0x15c/0x6a0 kernel/fork.c:2636 __do_sys_clone kernel/fork.c:2753 [inline] __se_sys_clone kernel/fork.c:2737 [inline] __x64_sys_clone+0xc6/0xf0 kernel/fork.c:2737 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f74eb205049 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f74ea97b118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f74eb317f60 RCX: 00007f74eb205049 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000007a988000 RBP: 00007f74ea97b1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000002 R13: 00007ffeadfe2aaf R14: 00007f74ea97b300 R15: 0000000000022000