================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:646 [inline] BUG: KASAN: slab-use-after-free in string+0x398/0x3d0 lib/vsprintf.c:728 Read of size 1 at addr ffff88802b2ff880 by task udevd/5271 CPU: 0 PID: 5271 Comm: udevd Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 string_nocheck lib/vsprintf.c:646 [inline] string+0x398/0x3d0 lib/vsprintf.c:728 vsnprintf+0xc67/0x1870 lib/vsprintf.c:2824 add_uevent_var+0x17c/0x3a0 lib/kobject_uevent.c:664 dev_uevent+0x18b/0x770 drivers/base/core.c:2672 uevent_show+0x1c7/0x390 drivers/base/core.c:2743 dev_attr_show+0x53/0xe0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x223/0x3e0 fs/sysfs/file.c:59 seq_read_iter+0x4fa/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x41a/0x590 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x869/0xbd0 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f950fb88b6a 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:00007ffdc00fbe88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000558b2a7b87d0 RCX: 00007f950fb88b6a RDX: 0000000000001000 RSI: 0000558b2a7ce990 RDI: 0000000000000008 RBP: 0000558b2a7b87d0 R08: 0000000000000008 R09: 0000000000000040 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffdc00fc368 R15: 000000000000000a Allocated by task 5382: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:660 [inline] raw_ioctl_init+0x162/0x7a0 drivers/usb/gadget/legacy/raw_gadget.c:509 raw_ioctl+0xc26/0x2a30 drivers/usb/gadget/legacy/raw_gadget.c:1303 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 5382: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2196 [inline] slab_free mm/slub.c:4437 [inline] kfree+0x12a/0x3b0 mm/slub.c:4558 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:211 kref_put include/linux/kref.h:65 [inline] raw_release+0x188/0x2f0 drivers/usb/gadget/legacy/raw_gadget.c:473 __fput+0x408/0xbb0 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa9b/0x2ba0 kernel/exit.c:874 do_group_exit+0xd3/0x2a0 kernel/exit.c:1023 get_signal+0x25c3/0x2670 kernel/signal.c:2909 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff88802b2ff880 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of freed 32-byte region [ffff88802b2ff880, ffff88802b2ff8a0) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b2ff ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 00fff00000000000 ffff888015442780 ffffea0000bbb380 dead000000000003 raw: 0000000000000000 0000000000400040 00000001ffffefff 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5228, tgid 5228 (syz-executor.2), ts 51436373252, free_ts 51287975539 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x136a/0x2e50 mm/page_alloc.c:3420 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4678 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2265 allocate_slab mm/slub.c:2428 [inline] new_slab+0x84/0x260 mm/slub.c:2481 ___slab_alloc+0xdac/0x1870 mm/slub.c:3667 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757 __slab_alloc_node mm/slub.c:3810 [inline] slab_alloc_node mm/slub.c:3989 [inline] kmalloc_trace_noprof+0x2c5/0x310 mm/slub.c:4148 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] ref_tracker_alloc+0x17c/0x5b0 lib/ref_tracker.c:203 __netdev_tracker_alloc include/linux/netdevice.h:4038 [inline] netdev_tracker_alloc include/linux/netdevice.h:4050 [inline] netdev_get_by_index+0x7c/0xb0 net/core/dev.c:912 fib6_nh_init+0x792/0x1db0 net/ipv6/route.c:3543 ip6_route_info_create+0x11e6/0x1ae0 net/ipv6/route.c:3809 ip6_route_add+0x26/0x190 net/ipv6/route.c:3853 addrconf_prefix_route+0x2fe/0x510 net/ipv6/addrconf.c:2485 fixup_permanent_addr net/ipv6/addrconf.c:3600 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3624 [inline] addrconf_notify+0x12e0/0x19e0 net/ipv6/addrconf.c:3696 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 page last free pid 5228 tgid 5228 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2583 __put_partials+0x14c/0x170 mm/slub.c:2995 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3941 [inline] slab_alloc_node mm/slub.c:4001 [inline] __do_kmalloc_node mm/slub.c:4121 [inline] kmalloc_node_track_caller_noprof+0x1c1/0x440 mm/slub.c:4142 kstrdup+0x3c/0x80 mm/util.c:62 device_rename+0x88/0x1e0 drivers/base/core.c:4567 dev_change_name+0x32c/0x9c0 net/core/dev.c:1246 do_setlink+0x2f04/0x3ea0 net/core/rtnetlink.c:2880 __rtnl_newlink+0xc3a/0x1960 net/core/rtnetlink.c:3696 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x542/0x820 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1905 Memory state around the buggy address: ffff88802b2ff780: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ffff88802b2ff800: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc >ffff88802b2ff880: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff88802b2ff900: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ffff88802b2ff980: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ==================================================================