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 ffff88811d43e64c by task udevd/7496 CPU: 1 PID: 7496 Comm: udevd Not tainted 6.4.0-rc5-syzkaller-g18af4b5c9791 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __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: 0033:0x7f4fb9e03b6a 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:00007fff6b138828 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000560e89dc5fe0 RCX: 00007f4fb9e03b6a RDX: 0000000000001000 RSI: 0000560e89ddb2c0 RDI: 0000000000000008 RBP: 0000560e89dc5fe0 R08: 0000000000000008 R09: 0000000000000400 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fff6b138d08 R15: 000000000000000a Allocated by task 13952: 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+0x7b/0x90 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 13950: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x144/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook mm/slub.c:1807 [inline] slab_free mm/slub.c:3786 [inline] __kmem_cache_free+0x99/0x320 mm/slub.c:3799 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+0xaa3/0x2910 kernel/exit.c:874 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 get_signal+0x2324/0x25c0 kernel/signal.c:2876 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+0x116/0x1f0 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 ffff88811d43e640 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 12 bytes inside of freed 32-byte region [ffff88811d43e640, ffff88811d43e660) The buggy address belongs to the physical page: page:ffffea0004750f80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d43e flags: 0x200000000000200(slab|node=0|zone=2) page_type: 0xffffffff() raw: 0200000000000200 ffff888100041500 ffffea00044c0140 dead000000000002 raw: 0000000000000000 0000000080400040 00000001ffffffff 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5247, tgid 5241 (syz-executor.1), ts 116592992543, free_ts 115422381182 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+0x13a1/0x2aa0 mm/page_alloc.c:3502 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] __kmem_cache_alloc_node+0x291/0x2d0 mm/slub.c:3490 __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 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+0x613/0xc80 mm/page_alloc.c:2564 free_unref_page+0x33/0x2a0 mm/page_alloc.c:2659 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2636 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x45/0x60 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/slub.c:3451 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x177/0x370 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] lsm_file_alloc security/security.c:611 [inline] security_file_alloc+0x38/0x170 security/security.c:2564 __alloc_file+0xd9/0x270 fs/file_table.c:144 alloc_empty_file+0x71/0x190 fs/file_table.c:188 path_openat+0xe6/0x2750 fs/namei.c:3777 do_filp_open+0x1ba/0x410 fs/namei.c:3818 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1383 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: ffff88811d43e500: fa fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff88811d43e580: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88811d43e600: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88811d43e680: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88811d43e700: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================