RBP: 00007fb0353d51d0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000004c890 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff466b7e9f R14: 00007fb0353d5300 R15: 0000000000022000
 </TASK>
------------[ cut here ]------------
WARNING: kernel/printk/printk_ringbuffer.c:1278 at get_data+0x364/0x400, CPU#1: syz-executor.7/97899
Modules linked in:
CPU: 1 UID: 0 PID: 97899 Comm: syz-executor.7 Not tainted 6.18.0-rc4-next-20251105 #1 PREEMPT(voluntary) 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:get_data+0x364/0x400
Code: e8 83 e0 07 83 c0 03 38 d0 0f 8c be fe ff ff 84 d2 0f 84 b6 fe ff ff 48 89 ef e8 a7 01 5c 00 e9 a9 fe ff ff e8 0d f8 1e 00 90 <0f> 0b 90 45 31 e4 e9 3b ff ff ff e8 fc f7 1e 00 90 0f 0b 90 45 31
RSP: 0018:ffff88806cf086b8 EFLAGS: 00010046
RAX: 0000000000010000 RBX: ffff88806cf087d0 RCX: ffffffff8155a316
RDX: ffff888050831bc0 RSI: ffffffff8155a4e3 RDI: 0000000000000006
RBP: ffff88806cf08798 R08: 0000000000000d5d R09: 0000025055511d18
R10: 0000000000000000 R11: 00017e6b82000019 R12: ffffffff85d2e590
R13: 00003fffffffffff R14: 0000000000000000 R15: 0000000000000000
FS:  00007fb0353d5700(0000) GS:ffff8880e54a5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb0353d4f78 CR3: 000000004e84d000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 _prb_read_valid+0x2f3/0x830
 prb_read_valid+0x78/0xa0
 printk_get_next_message+0x10b/0x570
 console_flush_one_record+0x64f/0xb20
 __console_flush_and_unlock+0xb1/0x1d0
 wake_up_klogd_work_func+0x17c/0x1e0
 irq_work_single+0x128/0x260
 irq_work_run_list+0x91/0xc0
 update_process_times+0x12f/0x210
 tick_nohz_handler+0x4ff/0x8c0
 __hrtimer_run_queues+0x60f/0xab0
 hrtimer_interrupt+0x369/0x830
 __sysvec_apic_timer_interrupt+0xbb/0x330
 sysvec_apic_timer_interrupt+0x6b/0x80
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:dump_stack_lvl+0x115/0x120
Code: fc ff ff 4c 89 e2 31 f6 31 ff e8 76 c3 6f fc e8 01 06 9a fc 48 89 ee 31 ff e8 97 16 ba fc e8 32 1b ba fc e8 1d 84 c2 fc fb 5b <5d> 41 5c e9 23 1b ba fc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffff8880508cf9a8 EFLAGS: 00000202
RAX: 0000000000000419 RBX: ffffffff8609e8a0 RCX: ffffffff817d04f6
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84ba81c3
RBP: 0000000000000200 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff86648957 R11: 0000000000000001 R12: ffffffff85520520
R13: ffffffff8609e8b0 R14: 0000000000000000 R15: 0000000000000000
 should_fail_ex+0x4d7/0x5e0
 _copy_from_user+0x30/0xd0
 copy_msghdr_from_user+0x88/0x150
 ___sys_sendmsg+0xdc/0x1b0
 __sys_sendmmsg+0x1f5/0x420
 __x64_sys_sendmmsg+0x9d/0x110
 do_syscall_64+0xbf/0x430
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb037e5fb19
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb0353d5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb037f72f60 RCX: 00007fb037e5fb19
RDX: 0000000000000003 RSI: 0000000020003040 RDI: 0000000000000003
RBP: 00007fb0353d51d0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000004c890 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff466b7e9f R14: 00007fb0353d5300 R15: 0000000000022000
 </TASK>
irq event stamp: 1050
hardirqs last  enabled at (1049): [<ffffffff84ba81c3>] dump_stack_lvl+0x113/0x120
hardirqs last disabled at (1050): [<ffffffff84c3b3cf>] sysvec_apic_timer_interrupt+0xf/0x80
softirqs last  enabled at (1044): [<ffffffff813bc08c>] handle_softirqs+0x50c/0x770
softirqs last disabled at (1025): [<ffffffff813bc424>] __irq_exit_rcu+0xc4/0x100
---[ end trace 0000000000000000 ]---
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 98197 Comm: syz-executor.7 Tainted: G        W           6.18.0-rc4-next-20251105 #1 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xfa/0x120
 should_fail_ex+0x4d7/0x5e0
 _copy_to_user+0x32/0xd0
 simple_read_from_buffer+0xe0/0x180
 proc_fail_nth_read+0x18a/0x240
 vfs_read+0x1eb/0xc70
 ksys_read+0x121/0x240
 do_syscall_64+0xbf/0x430
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb037e1269c
Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48
RSP: 002b:00007fb0353d5170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00007fb037e1269c
RDX: 000000000000000f RSI: 00007fb0353d51e0 RDI: 0000000000000004
RBP: 00007fb0353d51d0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000004c890 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff466b7e9f R14: 00007fb0353d5300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	ff 4c 89 e2          	decl   -0x1e(%rcx,%rcx,4)
   4:	31 f6                	xor    %esi,%esi
   6:	31 ff                	xor    %edi,%edi
   8:	e8 76 c3 6f fc       	callq  0xfc6fc383
   d:	e8 01 06 9a fc       	callq  0xfc9a0613
  12:	48 89 ee             	mov    %rbp,%rsi
  15:	31 ff                	xor    %edi,%edi
  17:	e8 97 16 ba fc       	callq  0xfcba16b3
  1c:	e8 32 1b ba fc       	callq  0xfcba1b53
  21:	e8 1d 84 c2 fc       	callq  0xfcc28443
  26:	fb                   	sti
  27:	5b                   	pop    %rbx
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	41 5c                	pop    %r12
  2b:	e9 23 1b ba fc       	jmpq   0xfcba1b53
  30:	0f 1f 00             	nopl   (%rax)
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop