================================================================== BUG: KASAN: use-after-free in usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1727 Read of size 8 at addr ffff88801dbba050 by task systemd-udevd/14053 CPU: 0 PID: 14053 Comm: systemd-udevd Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1727 dev_uevent+0x295/0x780 drivers/base/core.c:2297 uevent_show+0x1bb/0x390 drivers/base/core.c:2353 dev_attr_show+0x4b/0x90 drivers/base/core.c:2055 sysfs_kf_seq_show+0x1f8/0x400 fs/sysfs/file.c:61 seq_read_iter+0x4d4/0x11e0 fs/seq_file.c:227 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2108 [inline] new_sync_read+0x41e/0x6e0 fs/read_write.c:415 vfs_read+0x35c/0x570 fs/read_write.c:496 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe4f8987910 Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 de 9b 01 00 48 89 04 24 RSP: 002b:00007ffd3c5fd358 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055ccd2023e90 RCX: 00007fe4f8987910 RDX: 0000000000001000 RSI: 000055ccd201e230 RDI: 0000000000000007 RBP: 00007fe4f8c42440 R08: 00007fe4f8c461d8 R09: 0000000000001010 R10: 000055ccd2023e90 R11: 0000000000000246 R12: 0000000000001000 R13: 0000000000000d68 R14: 000055ccd201e230 R15: 00007fe4f8c41900 Allocated by task 13978: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] dev_new drivers/usb/gadget/legacy/raw_gadget.c:183 [inline] raw_open+0x8d/0x4d0 drivers/usb/gadget/legacy/raw_gadget.c:373 misc_open+0x372/0x4a0 drivers/char/misc.c:141 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_openat fs/open.c:1236 [inline] __se_sys_openat fs/open.c:1231 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1231 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 13978: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1636 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1661 slab_free mm/slub.c:3221 [inline] kfree+0xeb/0x650 mm/slub.c:4281 kref_put include/linux/kref.h:65 [inline] raw_release+0x218/0x290 drivers/usb/gadget/legacy/raw_gadget.c:412 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbd4/0x2a60 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88801dbba000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 80 bytes inside of 4096-byte region [ffff88801dbba000, ffff88801dbbb000) The buggy address belongs to the page: page:ffffea000076ee00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1dbb8 head:ffffea000076ee00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888010842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1045, ts 7428847725, free_ts 0 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5388 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 alloc_slab_page mm/slub.c:1699 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1839 new_slab mm/slub.c:1902 [inline] new_slab_objects mm/slub.c:2648 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2811 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2851 slab_alloc_node mm/slub.c:2933 [inline] kmem_cache_alloc_node_trace+0x18f/0x410 mm/slub.c:3017 kmalloc_node include/linux/slab.h:609 [inline] kzalloc_node include/linux/slab.h:732 [inline] bdi_alloc+0x43/0x140 mm/backing-dev.c:799 blk_alloc_queue+0xfd/0x700 block/blk-core.c:537 blk_mq_init_queue_data block/blk-mq.c:3118 [inline] __blk_mq_alloc_disk+0x47/0x190 block/blk-mq.c:3141 floppy_alloc_disk+0x34/0x370 drivers/block/floppy.c:4495 do_floppy_init drivers/block/floppy.c:4566 [inline] floppy_async_init+0x2ec/0x1f87 drivers/block/floppy.c:4731 async_run_entry_fn+0x9d/0x550 kernel/async.c:127 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 page_owner free stack trace missing Memory state around the buggy address: ffff88801dbb9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801dbb9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801dbba000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801dbba080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801dbba100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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