==================================================================
BUG: KASAN: out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
BUG: KASAN: out-of-bounds in put_bh include/linux/buffer_head.h:308 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc3/0xd0 fs/buffer.c:161
Write of size 4 at addr ffffc9000378f740 by task syz.1.2601/16120
CPU: 0 PID: 16120 Comm: syz.1.2601 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x220 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
put_bh include/linux/buffer_head.h:308 [inline]
end_buffer_read_sync+0xc3/0xd0 fs/buffer.c:161
end_bio_bh_io_sync+0xb7/0x110 fs/buffer.c:2784
req_bio_endio block/blk-mq.c:784 [inline]
blk_update_request+0x597/0xe40 block/blk-mq.c:929
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1056
blk_complete_reqs block/blk-mq.c:1136 [inline]
blk_done_softirq+0x10b/0x160 block/blk-mq.c:1141
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_call_function_single arch/x86/kernel/smp.c:262 [inline]
sysvec_call_function_single+0xa1/0xc0 arch/x86/kernel/smp.c:262
</IRQ>
<TASK>
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:694
RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254
Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 e9 f6 04 00 00 4c 8b 75 d0 4c 89 e7 e8 c0 a3 1a 09 e8 ab a2 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0000:ffffc9000444fc78 EFLAGS: 00000286
RAX: 475c07b61f18d700 RBX: 0000000000000000 RCX: 475c07b61f18d700
RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: ffffffff8afc66c0
RBP: ffffc9000444fcd0 R08: ffffffff8e4a882f R09: 1ffffffff1c95105
R10: dffffc0000000000 R11: fffffbfff1c95106 R12: ffff88802216bc00
R13: dffffc0000000000 R14: ffff88801ba45a00 R15: ffff8880b8e3cf08
context_switch kernel/sched/core.c:5383 [inline]
__schedule+0x14da/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
exit_to_user_mode_loop+0x47/0x110 kernel/entry/common.c:165
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:694
RIP: 0033:0x7f47e606802d
Code: 08 48 83 c3 08 48 39 d1 72 f3 48 83 e8 08 48 39 f2 73 17 66 2e 0f 1f 84 00 00 00 00 00 48 8b 70 f8 48 83 e8 08 48 39 f2 72 f3 <48> 39 c3 73 3e 48 89 33 48 83 c3 08 48 8b 70 f8 48 89 08 48 8b 0b
RSP: 002b:00007ffc40d7b0d0 EFLAGS: 00000216
RAX: 00007f47e5818f68 RBX: 00007f47e58125c8 RCX: ffffffff841d4422
RDX: ffffffff813aa799 RSI: ffffffff81009abe RDI: 00007f47e584f0f8
RBP: 00007f47e57fd010 R08: 00007f47e5826080 R09: 00007f47e63a2000
R10: 00007f47e57fd008 R11: 0000000000000009 R12: 00007f47e57fd008
R13: 000000000000001d R14: 000000000014aa66 R15: 00007f47e57fd008
</TASK>
The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003788000 allocated at copy_process+0x549/0x3d70 kernel/fork.c:2331
The buggy address belongs to the physical page:
page:ffffea0001a1b840 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x686e1
memcg:ffff88802edfb302
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88802edfb302
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 16086, tgid 16084 (syz.1.2590), ts 1348040312802, free_ts 1346454923953
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
vm_area_alloc_pages mm/vmalloc.c:3089 [inline]
__vmalloc_area_node mm/vmalloc.c:3158 [inline]
__vmalloc_node_range+0x96b/0x1320 mm/vmalloc.c:3339
alloc_thread_stack_node kernel/fork.c:310 [inline]
dup_task_struct+0x3d0/0x7c0 kernel/fork.c:1124
copy_process+0x549/0x3d70 kernel/fork.c:2331
kernel_clone+0x21b/0x840 kernel/fork.c:2914
__do_sys_clone kernel/fork.c:3057 [inline]
__se_sys_clone kernel/fork.c:3041 [inline]
__x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
tlb_batch_list_free mm/mmu_gather.c:114 [inline]
tlb_finish_mmu+0x112/0x1d0 mm/mmu_gather.c:395
exit_mmap+0x3f0/0xb50 mm/mmap.c:3311
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffffc9000378f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc9000378f680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000378f700: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 f2
^
ffffc9000378f780: f2 f2 f2 f2 00 f2 f2 f2 01 f3 f3 f3 00 00 00 00
ffffc9000378f800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 0f 84 37 01 00 00 je 0x13d
6: 48 85 db test %rbx,%rbx
9: 0f 85 56 01 00 00 jne 0x165
f: e9 f6 04 00 00 jmp 0x50a
14: 4c 8b 75 d0 mov -0x30(%rbp),%r14
18: 4c 89 e7 mov %r12,%rdi
1b: e8 c0 a3 1a 09 call 0x91aa3e0
20: e8 ab a2 2f 00 call 0x2fa2d0
25: fb sti
26: 4c 8b 65 c0 mov -0x40(%rbp),%r12
* 2a: 49 8d bc 24 f8 15 00 lea 0x15f8(%r12),%rdi <-- trapping instruction
31: 00
32: 48 89 f8 mov %rdi,%rax
35: 48 c1 e8 03 shr $0x3,%rax
39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
3e: 84 c0 test %al,%al