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 ffff888076a07644 by task udevd/4445

CPU: 0 PID: 4445 Comm: udevd Not tainted 6.4.0-rc3-syzkaller-00293-g416839029e38 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 string_nocheck lib/vsprintf.c:644 [inline]
 string+0x39c/0x3d0 lib/vsprintf.c:726
 vsnprintf+0xa36/0x1710 lib/vsprintf.c:2817
 add_uevent_var+0x161/0x390 lib/kobject_uevent.c:665
 dev_uevent+0x191/0x780 drivers/base/core.c:2575
 uevent_show+0x1bc/0x380 drivers/base/core.c:2646
 dev_attr_show+0x4f/0xd0 drivers/base/core.c:2349
 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:1862 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x4b1/0x8a0 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: 0033:0x7f7a96316b6a
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:00007ffe1ee714c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00005616c92f6c70 RCX: 00007f7a96316b6a
RDX: 0000000000001000 RSI: 00005616c9343ad0 RDI: 000000000000000c
RBP: 00005616c92f6c70 R08: 000000000000000c R09: 0000000000000020
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffe1ee719a8 R15: 000000000000000a
 </TASK>

Allocated by task 12734:
 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:559 [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 12733:
 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:3389 [inline]
 __do_kmem_cache_free mm/slab.c:3576 [inline]
 __kmem_cache_free+0xcd/0x2c0 mm/slab.c:3583
 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
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 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 ffff888076a07640
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 4 bytes inside of
 freed 32-byte region [ffff888076a07640, ffff888076a07660)

The buggy address belongs to the physical page:
page:ffffea0001da81c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888076a07fc1 pfn:0x76a07
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0x3f()
raw: 00fff00000000200 ffff888012440100 ffffea00008f3b10 ffffea0000a65910
raw: ffff888076a07fc1 ffff888076a07000 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 5297, tgid 5296 (syz-executor.0), ts 243036987308, free_ts 242864570954
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1731
 prep_new_page mm/page_alloc.c:1738 [inline]
 get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3502
 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 kmem_getpages mm/slab.c:1360 [inline]
 cache_grow_begin+0x9b/0x3b0 mm/slab.c:2569
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2942
 ____cache_alloc mm/slab.c:3018 [inline]
 ____cache_alloc mm/slab.c:3001 [inline]
 __do_cache_alloc mm/slab.c:3201 [inline]
 slab_alloc_node mm/slab.c:3249 [inline]
 __kmem_cache_alloc_node+0x360/0x3f0 mm/slab.c:3540
 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1057
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 ref_tracker_alloc+0x158/0x580 lib/ref_tracker.c:85
 __netdev_tracker_alloc include/linux/netdevice.h:4070 [inline]
 netdev_hold include/linux/netdevice.h:4099 [inline]
 ipv6_add_dev+0x455/0x13b0 net/ipv6/addrconf.c:401
 addrconf_notify+0x63d/0x19f0 net/ipv6/addrconf.c:3552
 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1935
 call_netdevice_notifiers_extack net/core/dev.c:1973 [inline]
 call_netdevice_notifiers net/core/dev.c:1987 [inline]
 register_netdevice+0xfb4/0x1640 net/core/dev.c:10118
 wg_newlink+0x425/0x920 drivers/net/wireguard/device.c:371
 rtnl_newlink_create net/core/rtnetlink.c:3443 [inline]
 __rtnl_newlink+0x10c2/0x1840 net/core/rtnetlink.c:3660
 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3673
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1302 [inline]
 free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2564
 free_unref_page+0x33/0x370 mm/page_alloc.c:2659
 slab_destroy mm/slab.c:1612 [inline]
 slabs_destroy+0x85/0xc0 mm/slab.c:1632
 cache_flusharray mm/slab.c:3360 [inline]
 ___cache_free+0x2ae/0x3d0 mm/slab.c:3423
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x4f/0x1a0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292
 __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:711 [inline]
 slab_alloc_node mm/slab.c:3256 [inline]
 __kmem_cache_alloc_node+0x1fc/0x3f0 mm/slab.c:3540
 __do_kmalloc_node mm/slab_common.c:965 [inline]
 __kmalloc+0x4e/0x190 mm/slab_common.c:979
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45
 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline]
 tomoyo_encode+0x2c/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x185/0x600 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x21a/0x570 security/tomoyo/file.c:723
 security_file_ioctl+0x54/0xb0 security/security.c:2608
 __do_sys_ioctl fs/ioctl.c:864 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0xb7/0x210 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

Memory state around the buggy address:
 ffff888076a07500: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff888076a07580: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff888076a07600: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
                                           ^
 ffff888076a07680: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888076a07700: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
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