================================================================== 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 ffff88801dff33c0 by task udevd/2976 CPU: 1 PID: 2976 Comm: udevd Not tainted 5.19.0-rc4-syzkaller-00014-g941e3e791269 #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:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 string_nocheck lib/vsprintf.c:643 [inline] string+0x39c/0x3d0 lib/vsprintf.c:725 vsnprintf+0x219/0x1660 lib/vsprintf.c:2782 add_uevent_var+0x15d/0x380 lib/kobject_uevent.c:665 dev_uevent+0x18d/0x780 drivers/base/core.c:2321 uevent_show+0x1b8/0x380 drivers/base/core.c:2392 dev_attr_show+0x4b/0x90 drivers/base/core.c:2095 sysfs_kf_seq_show+0x219/0x3d0 fs/sysfs/file.c:59 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x506/0x6e0 fs/kernfs/file.c:235 call_read_iter include/linux/fs.h:2052 [inline] new_sync_read+0x384/0x5f0 fs/read_write.c:401 vfs_read+0x492/0x5d0 fs/read_write.c:482 ksys_read+0x127/0x250 fs/read_write.c:620 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+0x46/0xb0 RIP: 0033:0x7efda69258fe 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:00007fff796c24a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005611eac97d50 RCX: 00007efda69258fe RDX: 0000000000001000 RSI: 00005611eac698f0 RDI: 000000000000000c RBP: 00007efda69f2380 R08: 000000000000000c R09: 00007efda69f5a60 R10: 0000000000000010 R11: 0000000000000246 R12: 00005611eac97d50 R13: 0000000000000d68 R14: 00007efda69f1780 R15: 0000000000000d68 Allocated by task 16474: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:600 [inline] raw_ioctl_init+0x152/0x830 drivers/usb/gadget/legacy/raw_gadget.c:460 raw_ioctl+0x8ef/0x2780 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+0x193/0x200 fs/ioctl.c:856 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+0x46/0xb0 Freed by task 16474: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3536 [inline] kfree+0xd6/0x4d0 mm/slub.c:4584 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:210 kref_put include/linux/kref.h:65 [inline] raw_release+0x219/0x290 drivers/usb/gadget/legacy/raw_gadget.c:424 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xaff/0x2a00 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x2542/0x2600 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The buggy address belongs to the object at ffff88801dff33c0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff88801dff33c0, ffff88801dff33e0) The buggy address belongs to the physical page: page:ffffea000077fcc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1dff3 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000001 ffff888011841500 raw: 0000000000000000 0000000000400040 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 3658, tgid 3658 (syz-executor.5), ts 217403153824, free_ts 217393648106 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x9c4/0xe20 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x310/0x3f0 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] ref_tracker_alloc+0x14c/0x550 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:3960 [inline] dev_hold_track include/linux/netdevice.h:3989 [inline] dev_hold_track include/linux/netdevice.h:3984 [inline] __netdev_adjacent_dev_insert+0x368/0xaa0 net/core/dev.c:7468 __netdev_adjacent_dev_link_lists net/core/dev.c:7556 [inline] __netdev_adjacent_dev_link_neighbour net/core/dev.c:7580 [inline] __netdev_upper_dev_link+0x3d6/0x7f0 net/core/dev.c:7640 netdev_master_upper_dev_link+0x98/0xd0 net/core/dev.c:7715 batadv_hardif_enable_interface+0x1d7/0xac0 net/batman-adv/hard-interface.c:712 batadv_softif_slave_add+0x64/0x130 net/batman-adv/soft-interface.c:839 do_set_master+0x1c8/0x220 net/core/rtnetlink.c:2577 do_setlink+0x9e7/0x3bb0 net/core/rtnetlink.c:2787 __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3546 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3438 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x26d/0x3f0 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] kobject_uevent_env+0x235/0x1660 lib/kobject_uevent.c:524 __kobject_del+0x169/0x200 lib/kobject.c:585 kobject_cleanup lib/kobject.c:664 [inline] kobject_release lib/kobject.c:704 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2b6/0x540 lib/kobject.c:721 netdev_queue_update_kobjects+0x367/0x4e0 net/core/net-sysfs.c:1733 netif_set_real_num_tx_queues+0x1b6/0x770 net/core/dev.c:2893 veth_init_queues+0xdd/0x190 drivers/net/veth.c:1691 veth_newlink+0x687/0x9a0 drivers/net/veth.c:1817 rtnl_newlink_create net/core/rtnetlink.c:3363 [inline] __rtnl_newlink+0x1087/0x17e0 net/core/rtnetlink.c:3580 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593 Memory state around the buggy address: ffff88801dff3280: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ffff88801dff3300: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88801dff3380: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88801dff3400: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ffff88801dff3480: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================