==================================================================
BUG: KASAN: out-of-bounds in i801_isr_byte_done drivers/i2c/busses/i2c-i801.c:597 [inline]
BUG: KASAN: out-of-bounds in i801_isr drivers/i2c/busses/i2c-i801.c:668 [inline]
BUG: KASAN: out-of-bounds in i801_isr+0xcfe/0xd60 drivers/i2c/busses/i2c-i801.c:649
Write of size 1 at addr ffffc9000af37d71 by task swapper/2/0

CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5/0x2f8 mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 i801_isr_byte_done drivers/i2c/busses/i2c-i801.c:597 [inline]
 i801_isr drivers/i2c/busses/i2c-i801.c:668 [inline]
 i801_isr+0xcfe/0xd60 drivers/i2c/busses/i2c-i801.c:649
 __handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:156
 handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
 handle_irq_event+0x102/0x290 kernel/irq/handle.c:213
 handle_fasteoi_irq+0x22f/0x9f0 kernel/irq/chip.c:714
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0x9e/0x200 arch/x86/kernel/irq.c:250
 common_interrupt+0x4c/0xd0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__do_softirq+0x196/0x9f6 kernel/softirq.c:331
Code: 00 48 01 f0 48 89 44 24 18 48 c7 c7 00 39 6a 89 e8 af 4c c3 ff 65 66 c7 05 35 46 c3 76 00 00 e8 00 e3 39 f8 fb b8 ff ff ff ff <48> c7 c3 c0 a0 c0 8b 41 0f bc c5 41 89 c7 41 83 c7 01 75 47 e9 d2
RSP: 0018:ffffc90000550f78 EFLAGS: 00000202
RAX: 00000000ffffffff RBX: ffff888010ca9c40 RCX: 1ffffffff1b89e11
RDX: 0000000000000000 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffff888010d59c40 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8179e4c8 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000282 R14: 0000000000000000 R15: 0000000000000000
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu kernel/softirq.c:422 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:default_idle+0xe/0x10 arch/x86/kernel/process.c:689
Code: ff ff ff 48 89 df e8 d1 15 b2 f8 e9 52 ff ff ff 4c 89 e7 e8 c4 15 b2 f8 eb 93 66 90 e9 07 00 00 00 0f 00 2d 04 53 60 00 fb f4 <c3> cc 41 55 41 54 55 48 89 fd 53 e8 c2 5a 6e f8 e8 7d b3 fd ff 48
RSP: 0018:ffffc9000043fdf8 EFLAGS: 00000206
RAX: 000000000008e481 RBX: ffff888010ca9c40 RCX: ffffffff890342b0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffed1002195388 R08: 0000000000000001 R09: ffff88802cc3610b
R10: ffffed1005986c21 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8dc52b08 R15: 0000000000000000
 default_idle_call+0x87/0xd0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x3fa/0x590 kernel/sched/idle.c:300
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397
 start_secondary+0x274/0x350 arch/x86/kernel/smpboot.c:272
 secondary_startup_64_no_verify+0xb0/0xbb


Memory state around the buggy address:
 ffffc9000af37c00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc9000af37c80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc9000af37d00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                                             ^
 ffffc9000af37d80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc9000af37e00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================