================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:646 [inline] BUG: KASAN: slab-use-after-free in string+0x394/0x3d0 lib/vsprintf.c:728 Read of size 1 at addr ffff88804fe8b648 by task udevd/4512 CPU: 1 PID: 4512 Comm: udevd Not tainted 6.7.0-rc3-next-20231129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:365 [inline] print_report+0xc3/0x620 mm/kasan/report.c:476 kasan_report+0xd9/0x110 mm/kasan/report.c:589 string_nocheck lib/vsprintf.c:646 [inline] string+0x394/0x3d0 lib/vsprintf.c:728 vsnprintf+0xc5f/0x1870 lib/vsprintf.c:2819 add_uevent_var+0x17c/0x3a0 lib/kobject_uevent.c:665 dev_uevent+0x18b/0x760 drivers/base/core.c:2576 uevent_show+0x1bf/0x380 drivers/base/core.c:2647 dev_attr_show+0x4f/0xd0 drivers/base/core.c:2350 sysfs_kf_seq_show+0x23e/0x400 fs/sysfs/file.c:59 seq_read_iter+0x4e5/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x410/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2076 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4d1/0x8f0 fs/read_write.c:470 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7f1f26f16b6a 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:00007fff10624678 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000561e1d213fe0 RCX: 00007f1f26f16b6a RDX: 0000000000001000 RSI: 0000561e1d225010 RDI: 000000000000000c RBP: 0000561e1d213fe0 R08: 000000000000000c R09: 0000000000000004 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fff10624b58 R15: 000000000000000a Allocated by task 11440: kasan_save_stack+0x33/0x50 mm/kasan/common.c:46 kasan_set_track+0x24/0x30 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:367 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:376 kmalloc include/linux/slab.h:590 [inline] raw_ioctl_init+0x163/0x840 drivers/usb/gadget/legacy/raw_gadget.c:509 raw_ioctl+0x9d9/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1303 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a Freed by task 11440: kasan_save_stack+0x33/0x50 mm/kasan/common.c:46 kasan_set_track+0x24/0x30 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:556 ____kasan_slab_free mm/kasan/common.c:229 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:193 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:2087 [inline] slab_free_freelist_hook+0x86/0x1f0 mm/slub.c:2113 slab_free mm/slub.c:4279 [inline] kfree+0xf3/0x2a0 mm/slub.c:4376 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:211 kref_put include/linux/kref.h:65 [inline] raw_release+0x184/0x2e0 drivers/usb/gadget/legacy/raw_gadget.c:473 __fput+0x270/0xbb0 fs/file_table.c:382 task_work_run+0x14c/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa85/0x2ad0 kernel/exit.c:871 do_group_exit+0xd3/0x2a0 kernel/exit.c:1021 get_signal+0x2395/0x2770 kernel/signal.c:2893 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11e/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x62/0x6a The buggy address belongs to the object at ffff88804fe8b640 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 8 bytes inside of freed 32-byte region [ffff88804fe8b640, ffff88804fe8b660) The buggy address belongs to the physical page: page:ffffea00013fa2c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4fe8b anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888013041500 0000000000000000 dead000000000001 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 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 9985, tgid 9981 (syz-executor.2), ts 686120697633, free_ts 681736352526 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1540 prep_new_page mm/page_alloc.c:1547 [inline] get_page_from_freelist+0xa19/0x3740 mm/page_alloc.c:3355 __alloc_pages+0x22e/0x2410 mm/page_alloc.c:4611 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 alloc_slab_page mm/slub.c:2158 [inline] allocate_slab mm/slub.c:2325 [inline] new_slab+0x283/0x3c0 mm/slub.c:2378 ___slab_alloc+0x4ab/0x1990 mm/slub.c:3511 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3596 __slab_alloc_node mm/slub.c:3649 [inline] slab_alloc_node mm/slub.c:3821 [inline] kmalloc_trace+0x2ff/0x330 mm/slub.c:3978 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] ref_tracker_alloc+0x17c/0x5a0 lib/ref_tracker.c:203 __netns_tracker_alloc include/net/net_namespace.h:333 [inline] netns_tracker_alloc include/net/net_namespace.h:342 [inline] nf_nat_masq_schedule.part.0+0x3e1/0x610 net/netfilter/nf_nat_masquerade.c:126 nf_nat_masq_schedule net/netfilter/nf_nat_masquerade.c:108 [inline] masq_inet6_event+0x203/0x250 net/netfilter/nf_nat_masquerade.c:295 notifier_call_chain+0xb6/0x3d0 kernel/notifier.c:93 atomic_notifier_call_chain+0x71/0x1b0 kernel/notifier.c:231 addrconf_ifdown.isra.0+0xeff/0x1c60 net/ipv6/addrconf.c:3929 addrconf_notify+0x232/0x1920 net/ipv6/addrconf.c:3727 notifier_call_chain+0xb6/0x3d0 kernel/notifier.c:93 page last free pid 9990 tgid 9987 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x51f/0xb10 mm/page_alloc.c:2390 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2530 __put_partials+0x14c/0x160 mm/slub.c:2893 qlink_free mm/kasan/quarantine.c:178 [inline] qlist_free_all+0xc1/0x1e0 mm/kasan/quarantine.c:194 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:301 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:298 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slub.c:3784 [inline] slab_alloc_node mm/slub.c:3831 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3838 getname_flags.part.0+0x50/0x4e0 fs/namei.c:140 getname_flags include/linux/audit.h:321 [inline] getname fs/namei.c:219 [inline] __do_sys_mkdirat fs/namei.c:4153 [inline] __se_sys_mkdirat fs/namei.c:4151 [inline] __x64_sys_mkdirat+0xff/0x170 fs/namei.c:4151 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a Memory state around the buggy address: ffff88804fe8b500: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88804fe8b580: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88804fe8b600: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88804fe8b680: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88804fe8b700: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc 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