================================================================== BUG: KASAN: use-after-free in strlen+0x53/0x60 lib/string.c:502 Read of size 1 at addr ffff888144f1a040 by task dhcpcd/3934 CPU: 0 PID: 3934 Comm: dhcpcd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 strlen+0x53/0x60 lib/string.c:502 nla_put_string+0x19/0x30 include/net/netlink.h:1522 rtnl_fill_ifinfo+0x1b8a/0x1d00 net/core/rtnetlink.c:1901 rtnl_dump_ifinfo+0xd80/0x1480 net/core/rtnetlink.c:2237 netlink_dump+0x683/0xcd0 net/netlink/af_netlink.c:2241 netlink_recvmsg+0x68f/0xe00 net/netlink/af_netlink.c:1959 ____sys_recvmsg+0x2c8/0x5b0 net/socket.c:-1 ___sys_recvmsg+0x210/0x590 net/socket.c:2780 __sys_recvmsg net/socket.c:2810 [inline] __do_sys_recvmsg net/socket.c:2820 [inline] __se_sys_recvmsg net/socket.c:2817 [inline] __x64_sys_recvmsg+0x20d/0x2e0 net/socket.c:2817 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd35d87a407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff8d04b9e0 EFLAGS: 00000202 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007fd35d7f0740 RCX: 00007fd35d87a407 RDX: 0000000000000000 RSI: 00007fff8d04ba70 RDI: 0000000000000019 RBP: 00007fff8d04ba54 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000001ff8 R13: 00007fff8d04ba60 R14: 00007fff8d04bb50 R15: 0000000000000000 Allocated by task 4435: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xb0/0x240 mm/slab_common.c:956 kvasprintf+0xe8/0x1a0 lib/kasprintf.c:25 kobject_set_name_vargs+0x5d/0x110 lib/kobject.c:265 dev_set_name+0xdf/0x130 drivers/base/core.c:3485 usb_add_gadget+0x474/0x6f0 drivers/usb/gadget/udc/core.c:1448 usb_add_gadget_udc_release+0x198/0x1e0 drivers/usb/gadget/udc/core.c:1506 dummy_udc_probe+0x686/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1102 platform_probe+0x137/0x1c0 drivers/base/platform.c:1400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x24a/0xb40 drivers/base/dd.c:638 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804 device_driver_attach+0xd9/0x1c0 drivers/base/dd.c:1131 bind_store+0x33b/0x380 drivers/base/bus.c:216 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x482/0x9a0 fs/read_write.c:584 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 4435: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 kobject_cleanup lib/kobject.c:687 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x25c/0x450 lib/kobject.c:729 dummy_udc_remove+0x54/0x60 drivers/usb/gadget/udc/dummy_hcd.c:1123 platform_remove+0x92/0xe0 drivers/base/platform.c:1422 device_remove drivers/base/dd.c:547 [inline] __device_release_driver drivers/base/dd.c:1279 [inline] device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305 unbind_store+0x2e2/0x300 drivers/base/bus.c:193 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x482/0x9a0 fs/read_write.c:584 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888144f1a040 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff888144f1a040, ffff888144f1a050) The buggy address belongs to the physical page: page:ffffea000513c680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x144f1a flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000000200 0000000000000000 dead000000000001 ffff8880174413c0 raw: 0000000000000000 0000000000800080 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 1, tgid 1 (swapper/0), ts 6721246115, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956 kstrdup mm/util.c:61 [inline] kstrdup_const+0x56/0x90 mm/util.c:84 __kernfs_new_node+0xa6/0x7f0 fs/kernfs/dir.c:610 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:690 kernfs_create_dir_ns+0x40/0x120 fs/kernfs/dir.c:1046 sysfs_create_dir_ns+0x12c/0x290 fs/sysfs/dir.c:59 create_dir lib/kobject.c:63 [inline] kobject_add_internal+0x617/0xca0 lib/kobject.c:231 kobject_add_varg lib/kobject.c:366 [inline] kobject_add+0x160/0x230 lib/kobject.c:418 page_owner free stack trace missing Memory state around the buggy address: ffff888144f19f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888144f19f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888144f1a000: 00 03 fc fc 00 03 fc fc fa fb fc fc 00 00 fc fc ^ ffff888144f1a080: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ffff888144f1a100: 00 06 fc fc 00 06 fc fc 00 06 fc fc 00 07 fc fc ==================================================================