==================================================================
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:304 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
Write of size 4 at addr ffffc9000bd9f720 by task ksoftirqd/1/23
CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xb4/0x290 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x29a/0x2b0 mm/kasan/generic.c:189
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:304 [inline]
end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2781
blk_update_request+0x5ee/0xe80 block/blk-mq.c:983
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145
blk_complete_reqs block/blk-mq.c:1220 [inline]
blk_done_softirq+0x10a/0x160 block/blk-mq.c:1225
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5250
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 6f 00 c7 09 e8 6a 66 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900001d7ad8 EFLAGS: 00000286
RAX: 0750a9c73d242400 RBX: 0000000000000000 RCX: 0750a9c73d242400
RDX: 0000000000000000 RSI: ffffffff8d74e0a0 RDI: ffffffff8bc1f340
RBP: ffffc900001d7b30 R08: ffffffff8f7f3077 R09: 1ffffffff1efe60e
R10: dffffc0000000000 R11: fffffbfff1efe60f R12: ffff88801c6eda00
R13: dffffc0000000000 R14: ffff888029b18000 R15: ffff8880b893a6d8
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0x16ea/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
smpboot_thread_fn+0x5bd/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the virtual mapping at
[ffffc9000bd98000, ffffc9000bda1000) created by:
copy_process+0x544/0x3b80 kernel/fork.c:2259
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x68e04
memcg:ffff88802a50b982
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88802a50b982
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 9396, tgid 9396 (syz.2.715), ts 401913089331, free_ts 401828985432
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
prep_new_page mm/page_alloc.c:1726 [inline]
get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3688
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2392
vm_area_alloc_pages mm/vmalloc.c:3592 [inline]
__vmalloc_area_node mm/vmalloc.c:3670 [inline]
__vmalloc_node_range_noprof+0x8fe/0x12c0 mm/vmalloc.c:3845
__vmalloc_node_noprof+0x7d/0x90 mm/vmalloc.c:3908
alloc_thread_stack_node kernel/fork.c:314 [inline]
dup_task_struct+0x3e7/0x860 kernel/fork.c:1136
copy_process+0x544/0x3b80 kernel/fork.c:2259
kernel_clone+0x21e/0x870 kernel/fork.c:2844
__do_sys_clone3 kernel/fork.c:3148 [inline]
__se_sys_clone3+0x256/0x2d0 kernel/fork.c:3127
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 9391 tgid 9391 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1262 [inline]
__free_frozen_pages+0xb0e/0xcd0 mm/page_alloc.c:2725
tlb_batch_list_free mm/mmu_gather.c:159 [inline]
tlb_finish_mmu+0x112/0x1d0 mm/mmu_gather.c:499
exit_mmap+0x474/0xba0 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffffc9000bd9f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc9000bd9f680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000bd9f700: f1 f1 f1 f1 00 00 00 00 00 00 00 f2 f2 f2 f2 f2
^
ffffc9000bd9f780: 00 f2 f2 f2 01 f3 f3 f3 00 00 00 00 00 00 00 00
ffffc9000bd9f800: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3
==================================================================
----------------
Code disassembly (best guess):
0: 0f 84 3c 01 00 00 je 0x142
6: 48 85 db test %rbx,%rbx
9: 0f 85 63 01 00 00 jne 0x172
f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
14: 4c 8b 75 d0 mov -0x30(%rbp),%r14
18: 4c 89 e7 mov %r12,%rdi
1b: e8 6f 00 c7 09 call 0x9c7008f
20: e8 6a 66 35 00 call 0x35668f
25: fb sti
26: 4c 8b 65 c0 mov -0x40(%rbp),%r12
* 2a: 49 8d bc 24 18 16 00 lea 0x1618(%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