================================================================== 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 ffff8880208d0340 by task udevd/12109 CPU: 1 PID: 12109 Comm: udevd Not tainted 6.1.0-rc5-syzkaller-00103-g81ac25651a62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 string_nocheck lib/vsprintf.c:643 [inline] string+0x39c/0x3d0 lib/vsprintf.c:725 vsnprintf+0xa11/0x16b0 lib/vsprintf.c:2800 add_uevent_var+0x161/0x390 lib/kobject_uevent.c:665 dev_uevent+0x191/0x780 drivers/base/core.c:2421 uevent_show+0x1bc/0x380 drivers/base/core.c:2492 dev_attr_show+0x4f/0x90 drivers/base/core.c:2195 sysfs_kf_seq_show+0x21d/0x3d0 fs/sysfs/file.c:59 seq_read_iter+0x4f9/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x546/0x7a0 fs/kernfs/file.c:275 call_read_iter include/linux/fs.h:2185 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x681/0x930 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: 0033:0x7fd67c7258fe 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:00007ffd4fb36ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000560693263cd0 RCX: 00007fd67c7258fe RDX: 0000000000001000 RSI: 0000560693273a90 RDI: 0000000000000008 RBP: 00007fd67c7f2380 R08: 0000000000000008 R09: 00007fd67c7f5a60 R10: 0000000000000020 R11: 0000000000000246 R12: 0000560693263cd0 R13: 0000000000000d68 R14: 00007fd67c7f1780 R15: 0000000000000d68 Allocated by task 12107: 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:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:553 [inline] raw_ioctl_init+0x152/0x820 drivers/usb/gadget/legacy/raw_gadget.c:460 raw_ioctl+0xbf5/0x27d0 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 12107: 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:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3674 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:210 kref_put include/linux/kref.h:65 [inline] raw_release+0x21d/0x290 drivers/usb/gadget/legacy/raw_gadget.c:424 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb3d/0x2a30 kernel/exit.c:820 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x21b1/0x2440 kernel/signal.c:2858 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 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 ffff8880208d0340 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880208d0340, ffff8880208d0360) The buggy address belongs to the physical page: page:ffffea0000823400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880208d0100 pfn:0x208d0 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000195e7c0 dead000000000002 ffff888012041500 raw: ffff8880208d0100 0000000080400036 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 0x116cc0(GFP_USER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY), pid 10942, tgid 10938 (syz-executor.2), ts 511743070872, free_ts 486125917699 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4288 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5555 __alloc_pages_node include/linux/gfp.h:223 [inline] alloc_slab_page mm/slub.c:1796 [inline] allocate_slab+0x80/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x199/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node+0x4d/0xd0 mm/slab_common.c:962 kmalloc_array_node include/linux/slab.h:666 [inline] kcalloc_node include/linux/slab.h:671 [inline] memcg_alloc_slab_cgroups+0x8f/0x150 mm/memcontrol.c:2885 account_slab mm/slab.h:635 [inline] allocate_slab+0x270/0x300 mm/slub.c:1957 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x199/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node+0x4d/0xd0 mm/slab_common.c:962 kmalloc_node include/linux/slab.h:579 [inline] kvmalloc_node+0x43/0x1b0 mm/util.c:581 kvmalloc include/linux/slab.h:706 [inline] kvzalloc include/linux/slab.h:714 [inline] alloc_netdev_mqs+0x9c/0x1180 net/core/dev.c:10588 __ip_tunnel_create+0x201/0x570 net/ipv4/ip_tunnel.c:254 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page_list+0x176/0xc40 mm/page_alloc.c:3529 release_pages+0xc8a/0x1360 mm/swap.c:1055 __pagevec_release+0x7b/0x110 mm/swap.c:1075 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] truncate_inode_pages_range+0x326/0x1030 mm/truncate.c:373 kill_bdev block/bdev.c:76 [inline] blkdev_flush_mapping+0x140/0x2f0 block/bdev.c:662 blkdev_put_whole+0xd1/0xf0 block/bdev.c:693 blkdev_put+0x22a/0x770 block/bdev.c:953 blkdev_close+0x68/0x80 block/fops.c:499 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880208d0200: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ffff8880208d0280: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc >ffff8880208d0300: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff8880208d0380: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8880208d0400: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================