==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:632 [inline]
BUG: KASAN: slab-use-after-free in string+0x4a6/0x4f0 lib/vsprintf.c:714
Read of size 1 at addr ffff88803e895ea0 by task udevd/6903

CPU: 1 UID: 0 PID: 6903 Comm: udevd Not tainted 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #0
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:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 string_nocheck lib/vsprintf.c:632 [inline]
 string+0x4a6/0x4f0 lib/vsprintf.c:714
 vsnprintf+0x4c8/0x1180 lib/vsprintf.c:2843
 add_uevent_var+0x17c/0x3a0 lib/kobject_uevent.c:679
 ib_device_uevent+0x4e/0xb0 drivers/infiniband/core/device.c:502
 dev_uevent+0x28b/0x770 drivers/base/core.c:2673
 uevent_show+0x1d8/0x3b0 drivers/base/core.c:2731
 dev_attr_show+0x53/0xe0 drivers/base/core.c:2423
 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59
 seq_read_iter+0x4f4/0x12b0 fs/seq_file.c:230
 kernfs_fop_read_iter+0x414/0x580 fs/kernfs/file.c:279
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x886/0xbf0 fs/read_write.c:565
 ksys_read+0x12b/0x250 fs/read_write.c:708
 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: 0033:0x7f7681378b6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffcbdf9d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055efbec7de20 RCX: 00007f7681378b6a
RDX: 0000000000001000 RSI: 000055efbeca9490 RDI: 0000000000000008
RBP: 000055efbec7de20 R08: 0000000000000008 R09: 0000000000020000
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffcbdf9d518 R15: 000000000000000a
 </TASK>

Allocated by task 12483:
 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:4294 [inline]
 __kmalloc_node_track_caller_noprof+0x222/0x510 mm/slub.c:4313
 __kmemdup_nul mm/util.c:61 [inline]
 kstrdup+0x53/0x100 mm/util.c:81
 kstrdup_const+0x63/0x80 mm/util.c:101
 kvasprintf_const+0x164/0x1a0 lib/kasprintf.c:46
 kobject_set_name_vargs+0x5a/0x140 lib/kobject.c:274
 dev_set_name+0xc8/0x100 drivers/base/core.c:3468
 assign_name drivers/infiniband/core/device.c:1202 [inline]
 ib_register_device+0x7e0/0xdf0 drivers/infiniband/core/device.c:1384
 siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline]
 siw_newlink drivers/infiniband/sw/siw/siw_main.c:431 [inline]
 siw_newlink+0xb60/0xd70 drivers/infiniband/sw/siw/siw_main.c:413
 nldev_newlink+0x38e/0x660 drivers/infiniband/core/nldev.c:1795
 rdma_nl_rcv_msg+0x388/0x6e0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2e6/0x450 drivers/infiniband/core/netlink.c:239
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:733 [inline]
 ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
 __sys_sendmsg+0x16e/0x220 net/socket.c:2659
 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

Freed by task 12485:
 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:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 kfree_const+0x55/0x60 mm/util.c:43
 kobject_rename+0x179/0x260 lib/kobject.c:524
 device_rename+0x130/0x230 drivers/base/core.c:4525
 ib_device_rename+0x114/0x5c0 drivers/infiniband/core/device.c:402
 nldev_set_doit+0x3be/0x4c0 drivers/infiniband/core/nldev.c:1146
 rdma_nl_rcv_msg+0x388/0x6e0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2e6/0x450 drivers/infiniband/core/netlink.c:239
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:733 [inline]
 ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
 __sys_sendmsg+0x16e/0x220 net/socket.c:2659
 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

The buggy address belongs to the object at ffff88803e895ea0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 freed 8-byte region [ffff88803e895ea0, ffff88803e895ea8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3e895
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b042500 ffffea0000a05a00 dead000000000002
raw: 0000000000000000 0000000000800080 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 11986, tgid 11985 (syz.1.1513), ts 150711065425, free_ts 150704805794
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_noprof+0x2f0/0x510 mm/slub.c:4300
 __kvmalloc_node_noprof+0xad/0x1a0 mm/util.c:662
 kvmalloc_array_node_noprof include/linux/slab.h:1063 [inline]
 __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:471 [inline]
 ptr_ring_resize_multiple_bh_noprof include/linux/ptr_ring.h:634 [inline]
 skb_array_resize_multiple_bh_noprof include/linux/skb_array.h:208 [inline]
 pfifo_fast_change_tx_queue_len+0x157/0xbb0 net/sched/sch_generic.c:909
 qdisc_change_tx_queue_len net/sched/sch_generic.c:1410 [inline]
 dev_qdisc_change_tx_queue_len+0x166/0x380 net/sched/sch_generic.c:1457
 dev_change_tx_queue_len+0x1a3/0x1e0 net/core/dev.c:9362
 dev_ifsioc+0xdfe/0x10d0 net/core/dev_ioctl.c:608
 dev_ioctl+0x224/0x10c0 net/core/dev_ioctl.c:826
 sock_do_ioctl+0x19e/0x280 net/socket.c:1213
 sock_ioctl+0x228/0x6c0 net/socket.c:1318
page last free pid 11986 tgid 11985 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 __put_partials+0x14c/0x170 mm/slub.c:3153
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __kmalloc_cache_noprof+0x243/0x410 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kmalloc_array_noprof include/linux/slab.h:945 [inline]
 ptr_ring_resize_multiple_bh_noprof include/linux/ptr_ring.h:629 [inline]
 skb_array_resize_multiple_bh_noprof include/linux/skb_array.h:208 [inline]
 pfifo_fast_change_tx_queue_len+0xe1/0xbb0 net/sched/sch_generic.c:909
 qdisc_change_tx_queue_len net/sched/sch_generic.c:1410 [inline]
 dev_qdisc_change_tx_queue_len+0x166/0x380 net/sched/sch_generic.c:1457
 dev_change_tx_queue_len+0x1a3/0x1e0 net/core/dev.c:9362
 dev_ifsioc+0xdfe/0x10d0 net/core/dev_ioctl.c:608
 dev_ioctl+0x224/0x10c0 net/core/dev_ioctl.c:826
 sock_do_ioctl+0x19e/0x280 net/socket.c:1213
 sock_ioctl+0x228/0x6c0 net/socket.c:1318
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
 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

Memory state around the buggy address:
 ffff88803e895d80: 05 fc fc fc fa fc fc fc 05 fc fc fc fa fc fc fc
 ffff88803e895e00: 05 fc fc fc 00 fc fc fc 05 fc fc fc fa fc fc fc
>ffff88803e895e80: 05 fc fc fc fa fc fc fc 05 fc fc fc 00 fc fc fc
                               ^
 ffff88803e895f00: 05 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc
 ffff88803e895f80: 05 fc fc fc 00 fc fc fc 05 fc fc fc fa fc fc fc
==================================================================