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BUG: KASAN: slab-out-of-bounds in nsim_dev_health_break_write+0x1be/0x1e0 drivers/net/netdevsim/health.c:156
Read of size 1 at addr ffff8880323361ff by task syz.4.4784/23883

CPU: 1 UID: 0 PID: 23883 Comm: syz.4.4784 Not tainted 6.13.0-rc3-syzkaller-00073-geabcdba3ad40 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 nsim_dev_health_break_write+0x1be/0x1e0 drivers/net/netdevsim/health.c:156
 full_proxy_write+0xfb/0x1b0 fs/debugfs/file.c:356
 vfs_write+0x24c/0x1150 fs/read_write.c:677
 ksys_write+0x12b/0x250 fs/read_write.c:731
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8017d85d29
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:00007f8018c48038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8017f76160 RCX: 00007f8017d85d29
RDX: 0000000000000000 RSI: 0000000020000900 RDI: 0000000000000007
RBP: 00007f8017e01aa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8017f76160 R15: 00007ffdffd44af8
 </TASK>

Allocated by task 1:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4298 [inline]
 __kmalloc_node_track_caller_noprof+0x21d/0x520 mm/slub.c:4317
 __kmemdup_nul mm/util.c:61 [inline]
 kstrdup+0x42/0xb0 mm/util.c:81
 kstrdup_const+0x63/0x80 mm/util.c:101
 __kernfs_new_node+0x9c/0x890 fs/kernfs/dir.c:620
 kernfs_new_node+0x186/0x240 fs/kernfs/dir.c:700
 kernfs_create_dir_ns+0x4c/0x150 fs/kernfs/dir.c:1061
 sysfs_create_dir_ns+0x13b/0x2b0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x2c8/0x990 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_init_and_add+0x11c/0x190 lib/kobject.c:457
 locate_module_kobject+0xf3/0x1a0 kernel/params.c:781
 kernel_add_sysfs_param kernel/params.c:808 [inline]
 param_sysfs_builtin kernel/params.c:856 [inline]
 param_sysfs_builtin_init+0x1e0/0x3c0 kernel/params.c:990
 do_one_initcall+0x128/0x630 init/main.c:1266
 do_initcall_level init/main.c:1328 [inline]
 do_initcalls init/main.c:1344 [inline]
 do_basic_setup init/main.c:1363 [inline]
 kernel_init_freeable+0x58f/0x8b0 init/main.c:1577
 kernel_init+0x1c/0x2b0 init/main.c:1466
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff8880323361e0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 26 bytes to the right of
 allocated 5-byte region [ffff8880323361e0, ffff8880323361e5)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32336
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801ac41500 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080800080 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 17757743355, free_ts 17724411782
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2269
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2589 [inline]
 new_slab+0x2c9/0x410 mm/slub.c:2642
 ___slab_alloc+0xce2/0x1650 mm/slub.c:3830
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __kmalloc_cache_noprof+0xf6/0x420 mm/slub.c:4324
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 add_sysfs_param+0x6c1/0x930 kernel/params.c:646
 kernel_add_sysfs_param kernel/params.c:817 [inline]
 param_sysfs_builtin kernel/params.c:856 [inline]
 param_sysfs_builtin_init+0x253/0x3c0 kernel/params.c:990
 do_one_initcall+0x128/0x630 init/main.c:1266
 do_initcall_level init/main.c:1328 [inline]
 do_initcalls init/main.c:1344 [inline]
 do_basic_setup init/main.c:1363 [inline]
 kernel_init_freeable+0x58f/0x8b0 init/main.c:1577
 kernel_init+0x1c/0x2b0 init/main.c:1466
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 25 tgid 25 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2657
 vfree+0x17a/0x890 mm/vmalloc.c:3382
 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3303
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888032336080: 06 fc fc fc 05 fc fc fc fa fc fc fc 07 fc fc fc
 ffff888032336100: 07 fc fc fc fa fc fc fc 03 fc fc fc 03 fc fc fc
>ffff888032336180: fa fc fc fc fa fc fc fc 05 fc fc fc 05 fc fc fc
                                                                ^
 ffff888032336200: 01 fc fc fc 07 fc fc fc 07 fc fc fc fa fc fc fc
 ffff888032336280: 06 fc fc fc 06 fc fc fc 06 fc fc fc fa fc fc fc
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