================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:644 [inline] BUG: KASAN: use-after-free in string+0x39c/0x3d0 lib/vsprintf.c:726 Read of size 1 at addr ffff88807dcced00 by task udevd/6135 CPU: 0 PID: 6135 Comm: udevd Not tainted 6.2.0-rc4-syzkaller-00009-gd532dd102151 #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:306 [inline] print_report+0x15e/0x461 mm/kasan/report.c:417 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 string_nocheck lib/vsprintf.c:644 [inline] string+0x39c/0x3d0 lib/vsprintf.c:726 vsnprintf+0xa11/0x16b0 lib/vsprintf.c:2796 add_uevent_var+0x161/0x390 lib/kobject_uevent.c:665 dev_uevent+0x191/0x780 drivers/base/core.c:2422 uevent_show+0x1bc/0x380 drivers/base/core.c:2493 dev_attr_show+0x4f/0x90 drivers/base/core.c:2196 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+0x53e/0x790 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2183 [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: 0033:0x7f4b25f258fe 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:00007fffc1efa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000056488972a070 RCX: 00007f4b25f258fe RDX: 0000000000001000 RSI: 0000564889739db0 RDI: 0000000000000008 RBP: 00007f4b25ff2380 R08: 0000000000000008 R09: 00007f4b25ff5a60 R10: 0000000000020000 R11: 0000000000000246 R12: 000056488972a070 R13: 0000000000000d68 R14: 00007f4b25ff1780 R15: 0000000000000d68 Allocated by task 6111: 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+0xa3/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [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 6111: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] __cache_free mm/slab.c:3394 [inline] __do_kmem_cache_free mm/slab.c:3580 [inline] __kmem_cache_free+0xcd/0x3b0 mm/slab.c:3587 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+0xaa8/0x2950 kernel/exit.c:867 do_group_exit+0xd4/0x2a0 kernel/exit.c:1012 get_signal+0x21c3/0x2450 kernel/signal.c:2859 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 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 ffff88807dcced00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff88807dcced00, ffff88807dcced20) The buggy address belongs to the physical page: page:ffffea0001f73380 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807dccefc1 pfn:0x7dcce flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff888012440100 ffffea00009e5bd0 ffffea0001df76d0 raw: ffff88807dccefc1 ffff88807dcce000 000000010000003f 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 0x242220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 5092, tgid 5092 (syz-executor.0), ts 200834845821, free_ts 200771635448 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 __alloc_pages_node include/linux/gfp.h:237 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x94/0x390 mm/slab.c:2574 cache_alloc_refill+0x27f/0x380 mm/slab.c:2947 ____cache_alloc mm/slab.c:3023 [inline] ____cache_alloc mm/slab.c:3006 [inline] __do_cache_alloc mm/slab.c:3206 [inline] slab_alloc_node mm/slab.c:3254 [inline] __kmem_cache_alloc_node+0x44f/0x510 mm/slab.c:3544 kmalloc_trace+0x26/0x60 mm/slab_common.c:1062 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] ref_tracker_alloc+0x158/0x560 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4020 [inline] netdev_tracker_alloc include/linux/netdevice.h:4032 [inline] fib6_nh_init+0x5ca/0x1bf0 net/ipv6/route.c:3621 ip6_route_info_create+0x10b0/0x18f0 net/ipv6/route.c:3799 addrconf_f6i_alloc+0x381/0x620 net/ipv6/route.c:4571 fixup_permanent_addr net/ipv6/addrconf.c:3461 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3500 [inline] addrconf_notify+0x1053/0x1c80 net/ipv6/addrconf.c:3572 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] __dev_notify_flags+0x120/0x2d0 net/core/dev.c:8569 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2827 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 slab_destroy mm/slab.c:1619 [inline] slabs_destroy+0x85/0xc0 mm/slab.c:1639 cache_flusharray mm/slab.c:3365 [inline] ___cache_free+0x2ac/0x3d0 mm/slab.c:3428 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1a0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:761 [inline] slab_alloc_node mm/slab.c:3261 [inline] kmem_cache_alloc_node+0x297/0x590 mm/slab.c:3532 __alloc_skb+0x216/0x310 net/core/skbuff.c:552 alloc_skb include/linux/skbuff.h:1270 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1202 [inline] netlink_sendmsg+0x9a6/0xe10 net/netlink/af_netlink.c:1907 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 __sys_sendto+0x23a/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125 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 Memory state around the buggy address: ffff88807dccec00: fa fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc ffff88807dccec80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc >ffff88807dcced00: fa fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc ^ ffff88807dcced80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff88807dccee00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================