================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:643 [inline] BUG: KASAN: slab-use-after-free in string+0x50/0xfc lib/vsprintf.c:726 Read at addr faff000023abc680 by task udevd/3573 Pointer tag: [fa], memory tag: [fe] CPU: 0 PID: 3573 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00269-g1b29d271614a #0 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x94/0xec arch/arm64/kernel/stacktrace.c:233 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x48/0x60 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:351 [inline] print_report+0xd8/0x5f4 mm/kasan/report.c:462 kasan_report+0x7c/0x9c mm/kasan/report.c:572 __do_kernel_fault+0x174/0x1c0 arch/arm64/mm/fault.c:320 do_bad_area arch/arm64/mm/fault.c:479 [inline] do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:790 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:866 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:586 string_nocheck lib/vsprintf.c:643 [inline] string+0x50/0xfc lib/vsprintf.c:726 vsnprintf+0x170/0x748 lib/vsprintf.c:2817 add_uevent_var+0x84/0x120 lib/kobject_uevent.c:665 dev_uevent+0x70/0x1e4 drivers/base/core.c:2575 uevent_show+0x8c/0x114 drivers/base/core.c:2646 dev_attr_show+0x20/0x6c drivers/base/core.c:2349 sysfs_kf_seq_show+0xac/0x124 fs/sysfs/file.c:59 kernfs_seq_show+0x2c/0x38 fs/kernfs/file.c:205 seq_read_iter+0x1cc/0x4d0 fs/seq_file.c:230 kernfs_fop_read_iter+0x150/0x1c4 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+0x1f4/0x284 fs/read_write.c:470 ksys_read+0x68/0xf4 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x1c/0x28 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0x38/0xa4 arch/arm64/kernel/syscall.c:193 el0_svc+0x2c/0xb0 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0xb8/0xbc arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:591 Allocated by task 5877: kasan_save_stack+0x2c/0x54 mm/kasan/common.c:45 save_stack_info+0x38/0x118 mm/kasan/tags.c:104 kasan_save_alloc_info+0x14/0x20 mm/kasan/tags.c:138 ____kasan_kmalloc mm/kasan/common.c:374 [inline] ____kasan_kmalloc mm/kasan/common.c:333 [inline] __kasan_kmalloc+0x9c/0xa8 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:196 [inline] kmalloc_trace+0x4c/0x60 mm/slab_common.c:1062 kmalloc include/linux/slab.h:559 [inline] raw_ioctl_init+0xfc/0x2d8 drivers/usb/gadget/legacy/raw_gadget.c:460 raw_ioctl+0x4c8/0xcb0 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] __arm64_sys_ioctl+0xa8/0xec fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0x38/0xa4 arch/arm64/kernel/syscall.c:193 el0_svc+0x2c/0xb0 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0xb8/0xbc arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:591 Freed by task 5874: kasan_save_stack+0x2c/0x54 mm/kasan/common.c:45 save_stack_info+0x38/0x118 mm/kasan/tags.c:104 kasan_save_free_info+0x18/0x24 mm/kasan/tags.c:143 ____kasan_slab_free.constprop.0+0x190/0x1f8 mm/kasan/common.c:236 __kasan_slab_free+0x10/0x1c mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0xb4/0x1e8 mm/slub.c:1807 slab_free mm/slub.c:3786 [inline] __kmem_cache_free+0x16c/0x2c0 mm/slub.c:3799 kfree+0x5c/0x74 mm/slab_common.c:1015 dev_free+0x30/0x118 drivers/usb/gadget/legacy/raw_gadget.c:210 kref_put include/linux/kref.h:65 [inline] raw_release+0xe0/0x16c drivers/usb/gadget/legacy/raw_gadget.c:424 __fput+0x78/0x258 fs/file_table.c:321 ____fput+0x10/0x1c fs/file_table.c:349 task_work_run+0x6c/0xc4 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x214/0x144c arch/arm64/kernel/signal.c:1304 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0xac/0xb0 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0xb8/0xbc arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:591 The buggy address belongs to the object at ffff000023abc680 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff000023abc680, ffff000023abc700) The buggy address belongs to the physical page: page:00000000f6983647 refcount:1 mapcount:0 mapping:0000000000000000 index:0xfaff000023abc680 pfn:0x63abc ksm flags: 0x1ffc00000000200(slab|node=0|zone=0|lastcpupid=0x7ff|kasantag=0x0) page_type: 0xffffffff() raw: 01ffc00000000200 fbff000002c01200 fffffc000023d8c0 dead000000000007 raw: faff000023abc680 000000008020001f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff000023abc400: f9 f9 fe fe fe fe fe fe f4 f4 f4 f4 f4 fe fe fe ffff000023abc500: fd fd fe fe fe fe fe fe f8 f8 f8 f8 f8 f8 f8 fe >ffff000023abc600: fc fc fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffff000023abc700: f1 f1 fe fe fe fe fe fe f6 f6 fe fe fe fe fe fe ffff000023abc800: f1 f1 fe fe fe fe fe fe f9 f9 fe fe fe fe fe fe 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