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BUG: KASAN: slab-out-of-bounds in fuse_retrieve fs/fuse/dev.c:1913 [inline]
BUG: KASAN: slab-out-of-bounds in fuse_notify_retrieve fs/fuse/dev.c:1961 [inline]
BUG: KASAN: slab-out-of-bounds in fuse_notify fs/fuse/dev.c:2069 [inline]
BUG: KASAN: slab-out-of-bounds in fuse_dev_do_write+0x3d9b/0x4da0 fs/fuse/dev.c:2160
Write of size 4 at addr ffff88807708c0dc by task syz.0.17/6039

CPU: 0 UID: 0 PID: 6039 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 fuse_retrieve fs/fuse/dev.c:1913 [inline]
 fuse_notify_retrieve fs/fuse/dev.c:1961 [inline]
 fuse_notify fs/fuse/dev.c:2069 [inline]
 fuse_dev_do_write+0x3d9b/0x4da0 fs/fuse/dev.c:2160
 fuse_dev_write+0x146/0x1d0 fs/fuse/dev.c:2244
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa5d478ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa5d5524038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa5d49b5fa0 RCX: 00007fa5d478ebe9
RDX: 0000000000000030 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007fa5d4811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa5d49b6038 R14: 00007fa5d49b5fa0 R15: 00007ffc1b29f678
 </TASK>

Allocated by task 6039:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x266/0x4b0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:913 [inline]
 kzalloc_noprof include/linux/slab.h:1043 [inline]
 fuse_retrieve fs/fuse/dev.c:1881 [inline]
 fuse_notify_retrieve fs/fuse/dev.c:1961 [inline]
 fuse_notify fs/fuse/dev.c:2069 [inline]
 fuse_dev_do_write+0x2f75/0x4da0 fs/fuse/dev.c:2160
 fuse_dev_write+0x146/0x1d0 fs/fuse/dev.c:2244
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807708c000
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 4 bytes to the right of
 allocated 216-byte region [ffff88807708c000, ffff88807708c0d8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7708c
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a841b40 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a841b40 dead000000000122 0000000000000000
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0001dc2301 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6039, tgid 6038 (syz.0.17), ts 79708895661, free_ts 79624068132
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x330 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0xbd1/0x13e0 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_noprof+0x2f1/0x4b0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:913 [inline]
 kzalloc_noprof include/linux/slab.h:1043 [inline]
 fuse_retrieve fs/fuse/dev.c:1881 [inline]
 fuse_notify_retrieve fs/fuse/dev.c:1961 [inline]
 fuse_notify fs/fuse/dev.c:2069 [inline]
 fuse_dev_do_write+0x2f75/0x4da0 fs/fuse/dev.c:2160
 fuse_dev_write+0x146/0x1d0 fs/fuse/dev.c:2244
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 15 tgid 15 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88807708bf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807708c000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807708c080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                    ^
 ffff88807708c100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807708c180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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