syzbot

loop6: detected capacity change from 0 to 32768
==================================================================
BUG: KASAN: slab-out-of-bounds in reiserfs_xattr_get+0xfe/0x5a0 fs/reiserfs/xattr.c:676
Read of size 8 at addr ffff88802519b598 by task syz.6.16199/11041

CPU: 1 PID: 11041 Comm: syz.6.16199 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 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
 reiserfs_xattr_get+0xfe/0x5a0 fs/reiserfs/xattr.c:676
 reiserfs_get_acl+0x7e/0x6a0 fs/reiserfs/xattr_acl.c:215
 __get_acl+0x26d/0x3f0 fs/posix_acl.c:160
 check_acl+0x3a/0x150 fs/namei.c:310
 acl_permission_check fs/namei.c:355 [inline]
 generic_permission+0x381/0x590 fs/namei.c:408
 do_inode_permission fs/namei.c:462 [inline]
 inode_permission+0x23d/0x480 fs/namei.c:529
 may_open+0x2e9/0x440 fs/namei.c:3260
 do_open fs/namei.c:3630 [inline]
 path_openat+0x25e4/0x3190 fs/namei.c:3789
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 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
RIP: 0033:0x7f5ca558d710
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 69 95 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 bc 95 02 00 8b 44
RSP: 002b:00007f5ca37f5df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007f5ca558d710
RDX: 0000000000010000 RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000001010006
R10: 0000000000000000 R11: 0000000000000293 R12: 0000200000000040
R13: 00007f5ca37f5eb0 R14: 000000000000628f R15: 0000200000000300
 </TASK>

Allocated by task 11041:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc+0xb4/0x240 mm/slab_common.c:1020
 kmalloc_array include/linux/slab.h:637 [inline]
 kcalloc include/linux/slab.h:668 [inline]
 __list_lru_init+0xa6/0x5f0 mm/list_lru.c:571
 alloc_super+0x779/0x920 fs/super.c:395
 sget+0x1ce/0x4d0 fs/super.c:897
 mount_bdev+0xec/0x2d0 fs/super.c:1623
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3377
 do_mount fs/namespace.c:3717 [inline]
 __do_sys_mount fs/namespace.c:3926 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903
 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

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452
 drop_sysctl_table+0x356/0x4b0 fs/proc/proc_sysctl.c:1515
 drop_sysctl_table+0x36d/0x4b0 fs/proc/proc_sysctl.c:1518
 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1536
 mpls_dev_sysctl_unregister+0x8b/0xc0 net/mpls/af_mpls.c:1431
 mpls_dev_notify+0x533/0x7a0 net/mpls/af_mpls.c:1643
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11086
 rtnl_delete_link net/core/rtnetlink.c:3259 [inline]
 rtnl_dellink+0x43c/0x730 net/core/rtnetlink.c:3311
 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 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

The buggy address belongs to the object at ffff88802519b400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes to the right of
 allocated 256-byte region [ffff88802519b400, ffff88802519b500)

The buggy address belongs to the physical page:
page:ffffea0000946680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2519a
head:ffffea0000946680 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5954, tgid 5954 (syz-executor), ts 84941724259, free_ts 84901276700
 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
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2081
 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 new_dir fs/proc/proc_sysctl.c:969 [inline]
 get_subdir fs/proc/proc_sysctl.c:1013 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1308 [inline]
 __register_sysctl_table+0xac9/0x1240 fs/proc/proc_sysctl.c:1389
 neigh_sysctl_register+0x9cc/0xab0 net/core/neighbour.c:3870
 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2670
 inetdev_init+0x2b4/0x4f0 net/ipv4/devinet.c:287
 inetdev_event+0x308/0x15c0 net/ipv4/devinet.c:1568
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 register_netdevice+0x160c/0x1ae0 net/core/dev.c:10313
 wg_newlink+0x48a/0x720 drivers/net/wireguard/device.c:373
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
 __slab_free+0x35e/0x410 mm/slub.c:3736
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3534
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 kobject_uevent_env+0x274/0x8c0 lib/kobject_uevent.c:539
 __kobject_del+0xd2/0x300 lib/kobject.c:601
 kobject_cleanup lib/kobject.c:680 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x239/0x470 lib/kobject.c:737
 netdev_queue_update_kobjects+0x3ed/0x480 net/core/net-sysfs.c:1760
 netif_set_real_num_tx_queues+0x183/0x8e0 net/core/dev.c:2969
 veth_init_queues+0x83/0x180 drivers/net/veth.c:1797
 veth_newlink+0x9a9/0xc30 drivers/net/veth.c:1920

Memory state around the buggy address:
 ffff88802519b480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802519b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802519b580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88802519b600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802519b680: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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