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BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:643 [inline]
BUG: KASAN: use-after-free in string+0x39c/0x3d0 lib/vsprintf.c:725
Read of size 1 at addr ffff8880265be840 by task udevd/2995

CPU: 0 PID: 2995 Comm: udevd Not tainted 6.1.0-rc7-syzkaller-00123-ga4412fdd49dc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15e/0x461 mm/kasan/report.c:395
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495
 string_nocheck lib/vsprintf.c:643 [inline]
 string+0x39c/0x3d0 lib/vsprintf.c:725
 vsnprintf+0xa11/0x16b0 lib/vsprintf.c:2800
 add_uevent_var+0x161/0x390 lib/kobject_uevent.c:665
 dev_uevent+0x191/0x780 drivers/base/core.c:2421
 uevent_show+0x1bc/0x380 drivers/base/core.c:2492
 dev_attr_show+0x4f/0x90 drivers/base/core.c:2195
 sysfs_kf_seq_show+0x21d/0x3d0 fs/sysfs/file.c:59
 seq_read_iter+0x4f9/0x1280 fs/seq_file.c:230
 kernfs_fop_read_iter+0x546/0x7a0 fs/kernfs/file.c:275
 call_read_iter include/linux/fs.h:2193 [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: 0033:0x7fb59af258fe
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:00007fffcd5f2c08 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000558da9f14070 RCX: 00007fb59af258fe
RDX: 0000000000001000 RSI: 0000558da9f41c70 RDI: 000000000000000c
RBP: 00007fb59aff2380 R08: 000000000000000c R09: 00007fb59aff5a60
R10: 0000000000000008 R11: 0000000000000246 R12: 0000558da9f14070
R13: 0000000000000d68 R14: 00007fb59aff1780 R15: 0000000000000d68
 </TASK>

Allocated by task 15315:
 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:371 [inline]
 ____kasan_kmalloc mm/kasan/common.c:330 [inline]
 __kasan_kmalloc+0xa3/0xb0 mm/kasan/common.c:380
 kmalloc include/linux/slab.h:553 [inline]
 raw_ioctl_init+0x152/0x820 drivers/usb/gadget/legacy/raw_gadget.c:460
 raw_ioctl+0xbf5/0x27d0 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 15315:
 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:511
 ____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:177 [inline]
 __cache_free mm/slab.c:3389 [inline]
 __do_kmem_cache_free mm/slab.c:3585 [inline]
 __kmem_cache_free+0xcd/0x3b0 mm/slab.c:3592
 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:210
 kref_put include/linux/kref.h:65 [inline]
 raw_release+0x21d/0x290 drivers/usb/gadget/legacy/raw_gadget.c:424
 __fput+0x27c/0xa90 fs/file_table.c:320
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xb3d/0x2a30 kernel/exit.c:820
 do_group_exit+0xd4/0x2a0 kernel/exit.c:950
 get_signal+0x21b1/0x2440 kernel/signal.c:2858
 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869
 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 ffff8880265be840
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8880265be840, ffff8880265be860)

The buggy address belongs to the physical page:
page:ffffea0000996f80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880265befc1 pfn:0x265be
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0001f977c8 ffffea0001d227c8 ffff888012040100
raw: ffff8880265befc1 ffff8880265be000 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 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 9970, tgid 9962 (syz-executor.2), ts 809030412072, free_ts 808890572749
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4291
 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5558
 __alloc_pages_node include/linux/gfp.h:223 [inline]
 kmem_getpages mm/slab.c:1363 [inline]
 cache_grow_begin+0x75/0x360 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+0x44a/0x510 mm/slab.c:3549
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:975
 kmemdup+0x2c/0x60 mm/util.c:129
 kmemdup include/linux/fortify-string.h:585 [inline]
 ip6_rthdr_dup net/ipv6/ip6_output.c:1345 [inline]
 ip6_setup_cork+0x734/0x1490 net/ipv6/ip6_output.c:1412
 ip6_make_skb+0x1f0/0x510 net/ipv6/ip6_output.c:2037
 udpv6_sendmsg+0x2099/0x2c80 net/ipv6/udp.c:1572
 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 ____sys_sendmsg+0x334/0x8c0 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmmsg+0x18f/0x460 net/socket.c:2622
 __do_sys_sendmmsg net/socket.c:2651 [inline]
 __se_sys_sendmmsg net/socket.c:2648 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2648
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483
 tlb_batch_list_free mm/mmu_gather.c:75 [inline]
 tlb_finish_mmu+0x1a7/0x7e0 mm/mmu_gather.c:366
 exit_mmap+0x202/0x7b0 mm/mmap.c:3105
 __mmput+0x128/0x4c0 kernel/fork.c:1185
 mmput+0x60/0x70 kernel/fork.c:1207
 copy_process+0x3161/0x7190 kernel/fork.c:2518
 kernel_clone+0xeb/0x980 kernel/fork.c:2671
 __do_sys_clone+0xba/0x100 kernel/fork.c:2812
 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

Memory state around the buggy address:
 ffff8880265be700: 00 00 00 00 fc fc fc fc 00 fc fc fc fc fc fc fc
 ffff8880265be780: 00 00 00 00 fc fc fc fc 00 00 00 fc fc fc fc fc
>ffff8880265be800: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
                                           ^
 ffff8880265be880: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff8880265be900: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
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