syzbot

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BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:644 [inline]
BUG: KASAN: slab-use-after-free in string+0x39c/0x3d0 lib/vsprintf.c:726
Read of size 1 at addr ffff8880299f6c05 by task udevd/4431

CPU: 1 PID: 4431 Comm: udevd Not tainted 6.3.0-rc3-syzkaller-00016-g2faac9a98f01 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319
 print_report mm/kasan/report.c:430 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:536
 string_nocheck lib/vsprintf.c:644 [inline]
 string+0x39c/0x3d0 lib/vsprintf.c:726
 vsnprintf+0xa36/0x1710 lib/vsprintf.c:2796
 add_uevent_var+0x161/0x390 lib/kobject_uevent.c:665
 dev_uevent+0x191/0x780 drivers/base/core.c:2527
 uevent_show+0x1bc/0x380 drivers/base/core.c:2598
 dev_attr_show+0x4f/0xd0 drivers/base/core.c:2301
 sysfs_kf_seq_show+0x21d/0x430 fs/sysfs/file.c:59
 seq_read_iter+0x4f9/0x12d0 fs/seq_file.c:230
 kernfs_fop_read_iter+0x4ce/0x690 fs/kernfs/file.c:279
 call_read_iter include/linux/fs.h:1845 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x681/0x930 fs/read_write.c:470
 ksys_read+0x12b/0x250 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f98813258fe
Code: c0 e9 e6 fe ff ff 50 48 8d 3d 0e c7 09 00 e8 c9 cf 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007fffc8b00f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00005599008c1110 RCX: 00007f98813258fe
RDX: 0000000000001000 RSI: 00005599008ce7e0 RDI: 000000000000000c
RBP: 00007f98813f2380 R08: 000000000000000c R09: 00007f98813f5a60
R10: 0000000002000000 R11: 0000000000000246 R12: 00005599008c1110
R13: 0000000000000d68 R14: 00007f98813f1780 R15: 0000000000000d68
 </TASK>

Allocated by task 18202:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 ____kasan_kmalloc mm/kasan/common.c:333 [inline]
 __kasan_kmalloc+0xa3/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:580 [inline]
 raw_ioctl_init+0x152/0x830 drivers/usb/gadget/legacy/raw_gadget.c:460
 raw_ioctl+0xbf5/0x2a60 drivers/usb/gadget/legacy/raw_gadget.c:1250
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 18202:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:521
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 __cache_free mm/slab.c:3390 [inline]
 __do_kmem_cache_free mm/slab.c:3577 [inline]
 __kmem_cache_free+0xcd/0x2c0 mm/slab.c:3584
 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:210
 kref_put include/linux/kref.h:65 [inline]
 raw_release+0x21d/0x2d0 drivers/usb/gadget/legacy/raw_gadget.c:424
 __fput+0x27c/0xa90 fs/file_table.c:321
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xad3/0x2960 kernel/exit.c:869
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019
 get_signal+0x2315/0x25b0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880299f6c00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 5 bytes inside of
 freed 32-byte region [ffff8880299f6c00, ffff8880299f6c20)

The buggy address belongs to the physical page:
page:ffffea0000a67d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880299f6fc1 pfn:0x299f6
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff888012440100 ffffea0000aa9a90 ffffea0001eac510
raw: ffff8880299f6fc1 ffff8880299f6000 000000010000003f 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 0x242020(__GFP_HIGH|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 5160, tgid 5160 (kworker/1:4), ts 286268768547, free_ts 286268603412
 prep_new_page mm/page_alloc.c:2552 [inline]
 get_page_from_freelist+0x1190/0x2e20 mm/page_alloc.c:4325
 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:5591
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 kmem_getpages mm/slab.c:1360 [inline]
 cache_grow_begin+0x9b/0x3b0 mm/slab.c:2570
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943
 ____cache_alloc mm/slab.c:3019 [inline]
 ____cache_alloc mm/slab.c:3002 [inline]
 __do_cache_alloc mm/slab.c:3202 [inline]
 slab_alloc_node mm/slab.c:3250 [inline]
 __kmem_cache_alloc_node+0x360/0x3f0 mm/slab.c:3541
 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1061
 kmalloc include/linux/slab.h:580 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 ref_tracker_alloc+0x158/0x580 lib/ref_tracker.c:85
 __netdev_tracker_alloc include/linux/netdevice.h:4038 [inline]
 netdev_hold include/linux/netdevice.h:4067 [inline]
 netdev_hold include/linux/netdevice.h:4062 [inline]
 ___neigh_create+0x7b2/0x2a40 net/core/neighbour.c:680
 ip6_finish_output2+0x1000/0x1590 net/ipv6/ip6_output.c:125
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x694/0x1170 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 NF_HOOK include/linux/netfilter.h:296 [inline]
 mld_sendpack+0xa09/0xed0 net/ipv6/mcast.c:1820
 mld_send_cr net/ipv6/mcast.c:2121 [inline]
 mld_ifc_work+0x73c/0xe20 net/ipv6/mcast.c:2653
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
 worker_thread+0x669/0x1090 kernel/workqueue.c:2537
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1453 [inline]
 free_pcp_prepare+0x5d5/0xa50 mm/page_alloc.c:1503
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page+0x1d/0x490 mm/page_alloc.c:3482
 slab_destroy mm/slab.c:1613 [inline]
 slabs_destroy+0x85/0xc0 mm/slab.c:1633
 cache_flusharray mm/slab.c:3361 [inline]
 ___cache_free+0x2ae/0x3d0 mm/slab.c:3424
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x4f/0x1a0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook mm/slab.h:769 [inline]
 slab_alloc_node mm/slab.c:3257 [inline]
 kmem_cache_alloc_node+0x296/0x510 mm/slab.c:3529
 __alloc_skb+0x288/0x330 net/core/skbuff.c:596
 alloc_skb include/linux/skbuff.h:1277 [inline]
 alloc_skb_with_frags+0x97/0x6c0 net/core/skbuff.c:6318
 sock_alloc_send_pskb+0x7a7/0x930 net/core/sock.c:2734
 sock_alloc_send_skb include/net/sock.h:1860 [inline]
 mld_newpack.isra.0+0x1b9/0x770 net/ipv6/mcast.c:1748
 add_grhead+0x295/0x340 net/ipv6/mcast.c:1851
 add_grec+0x1053/0x1610 net/ipv6/mcast.c:1989
 mld_send_cr net/ipv6/mcast.c:2115 [inline]
 mld_ifc_work+0x42c/0xe20 net/ipv6/mcast.c:2653
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390

Memory state around the buggy address:
 ffff8880299f6b00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
 ffff8880299f6b80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
>ffff8880299f6c00: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
                   ^
 ffff8880299f6c80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff8880299f6d00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
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