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BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:639 [inline]
BUG: KASAN: slab-use-after-free in string+0x4a4/0x4f0 lib/vsprintf.c:721
Read of size 1 at addr ffff888023b42d00 by task udevd/5350

CPU: 2 UID: 0 PID: 5350 Comm: udevd Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 string_nocheck lib/vsprintf.c:639 [inline]
 string+0x4a4/0x4f0 lib/vsprintf.c:721
 vsnprintf+0x4bc/0x1160 lib/vsprintf.c:2874
 add_uevent_var+0x183/0x3a0 lib/kobject_uevent.c:679
 ib_device_uevent+0x4e/0xb0 drivers/infiniband/core/device.c:502
 dev_uevent+0x26c/0x820 drivers/base/core.c:2703
 uevent_show+0x1c9/0x3a0 drivers/base/core.c:2759
 dev_attr_show+0x53/0xe0 drivers/base/core.c:2424
 sysfs_kf_seq_show+0x213/0x3e0 fs/sysfs/file.c:65
 seq_read_iter+0x506/0x12c0 fs/seq_file.c:230
 kernfs_fop_read_iter+0x40f/0x5a0 fs/kernfs/file.c:279
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x8bf/0xc60 fs/read_write.c:572
 ksys_read+0x12a/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f268daa7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc48a4a4f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f268e224880 RCX: 00007f268daa7407
RDX: 0000000000001000 RSI: 0000556a3f031ce0 RDI: 000000000000000c
RBP: 00007f268dbefff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007f268dbefea0 R14: 0000000000000000 R15: 0000556a3f027ee0
 </TASK>

Allocated by task 7374:
 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:4327 [inline]
 __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4346
 __kmemdup_nul mm/util.c:63 [inline]
 kstrdup+0x53/0x100 mm/util.c:83
 kstrdup_const+0x63/0x80 mm/util.c:103
 kvasprintf_const+0x164/0x1a0 lib/kasprintf.c:46
 kobject_set_name_vargs+0x5a/0x140 lib/kobject.c:274
 dev_set_name+0xc7/0x100 drivers/base/core.c:3495
 assign_name drivers/infiniband/core/device.c:1211 [inline]
 ib_register_device+0x7df/0xe00 drivers/infiniband/core/device.c:1401
 siw_device_register drivers/infiniband/sw/siw/siw_main.c:71 [inline]
 siw_newlink drivers/infiniband/sw/siw/siw_main.c:430 [inline]
 siw_newlink+0xb60/0xd70 drivers/infiniband/sw/siw/siw_main.c:412
 nldev_newlink+0x3a6/0x680 drivers/infiniband/core/nldev.c:1796
 rdma_nl_rcv_msg+0x38a/0x6e0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2d0/0x430 drivers/infiniband/core/netlink.c:239
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53d/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 7375:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4841
 kfree_const+0x55/0x60 mm/util.c:45
 kobject_rename+0x178/0x260 lib/kobject.c:524
 device_rename+0x130/0x230 drivers/base/core.c:4552
 ib_device_rename+0x113/0x5c0 drivers/infiniband/core/device.c:402
 nldev_set_doit+0x3d7/0x4e0 drivers/infiniband/core/nldev.c:1147
 rdma_nl_rcv_msg+0x38a/0x6e0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2d0/0x430 drivers/infiniband/core/netlink.c:239
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53d/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888023b42d00
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 freed 8-byte region [ffff888023b42d00, ffff888023b42d08)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888023b42b60 pfn:0x23b42
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b442500 ffffea00006d1780 dead000000000002
raw: ffff888023b42b60 0000000080800069 00000000f5000000 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 21366337808, free_ts 21361988410
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1710
 prep_new_page mm/page_alloc.c:1718 [inline]
 get_page_from_freelist+0x135c/0x3950 mm/page_alloc.c:3680
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4970
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab mm/slub.c:2618 [inline]
 new_slab+0x23b/0x330 mm/slub.c:2672
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 add_sysfs_param+0x765/0xa00 kernel/params.c:646
 kernel_add_sysfs_param kernel/params.c:811 [inline]
 param_sysfs_builtin kernel/params.c:850 [inline]
 param_sysfs_builtin_init+0x307/0x4c0 kernel/params.c:986
 do_one_initcall+0x120/0x6e0 init/main.c:1257
 do_initcall_level init/main.c:1319 [inline]
 do_initcalls init/main.c:1335 [inline]
 do_basic_setup init/main.c:1354 [inline]
 kernel_init_freeable+0x5c2/0x900 init/main.c:1567
 kernel_init+0x1c/0x2b0 init/main.c:1457
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 838 tgid 838 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1254 [inline]
 __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2717
 vfree+0x176/0xa40 mm/vmalloc.c:3416
 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3336
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 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:
 ffff888023b42c00: fa fc fc fc fa fc fc fc fa fc fc fc 05 fc fc fc
 ffff888023b42c80: fa fc fc fc fa fc fc fc fa fc fc fc 00 fc fc fc
>ffff888023b42d00: fa fc fc fc 05 fc fc fc fa fc fc fc 00 fc fc fc
                   ^
 ffff888023b42d80: 00 fc fc fc 00 fc fc fc 05 fc fc fc 05 fc fc fc
 ffff888023b42e00: 05 fc fc fc 05 fc fc fc 00 fc fc fc 00 fc fc fc
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