================================================================== BUG: KASAN: use-after-free in usb_udc_uevent+0xac/0x120 drivers/usb/gadget/udc/core.c:1600 Read of size 8 at addr ffff8881ee4e4010 by task udevd/1950 CPU: 0 PID: 1950 Comm: udevd Not tainted 5.4.161-syzkaller-00029-gffcfa2b78144 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18e/0x1de lib/dump_stack.c:118 print_address_description+0x9b/0x650 mm/kasan/report.c:384 __kasan_report+0x182/0x260 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 usb_udc_uevent+0xac/0x120 drivers/usb/gadget/udc/core.c:1600 dev_uevent+0x41c/0x5b0 drivers/base/core.c:1887 uevent_show+0x1a2/0x2e0 drivers/base/core.c:1943 dev_attr_show+0x50/0xc0 drivers/base/core.c:1647 sysfs_kf_seq_show+0x265/0x3e0 fs/sysfs/file.c:61 seq_read+0x4ca/0xda0 fs/seq_file.c:232 __vfs_read+0xa7/0x690 fs/read_write.c:425 vfs_read+0x161/0x370 fs/read_write.c:461 ksys_read+0x13f/0x240 fs/read_write.c:587 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8b7c1f18fe 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:00007ffef50a4ab8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055cea7d9e920 RCX: 00007f8b7c1f18fe RDX: 0000000000001000 RSI: 000055cea7daf9f0 RDI: 0000000000000008 RBP: 00007f8b7c2be380 R08: 0000000000000008 R09: 00007f8b7c2c1a60 R10: 0000000000000063 R11: 0000000000000246 R12: 000055cea7d9e920 R13: 0000000000000d68 R14: 00007f8b7c2bd780 R15: 0000000000000d68 Allocated by task 22519: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x137/0x1e0 mm/kasan/common.c:529 kmem_cache_alloc_trace+0x139/0x2b0 mm/slub.c:2856 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] dev_new drivers/usb/gadget/legacy/raw_gadget.c:182 [inline] raw_open+0x84/0x370 drivers/usb/gadget/legacy/raw_gadget.c:372 misc_open+0x346/0x3c0 drivers/char/misc.c:141 chrdev_open+0x4ec/0x5b0 fs/char_dev.c:414 do_dentry_open+0x7e6/0xef0 fs/open.c:796 do_last fs/namei.c:3495 [inline] path_openat+0xfed/0x3a50 fs/namei.c:3612 do_filp_open+0x19a/0x3a0 fs/namei.c:3642 do_sys_open+0x2e2/0x6d0 fs/open.c:1113 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 22518: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x18a/0x240 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0x80/0x150 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kfree+0xed/0x690 mm/slub.c:4071 raw_release+0x130/0x1e0 drivers/usb/gadget/legacy/raw_gadget.c:411 __fput+0x27d/0x6c0 fs/file_table.c:281 task_work_run+0x186/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x2b0/0x310 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8881ee4e4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 16 bytes inside of 4096-byte region [ffff8881ee4e4000, ffff8881ee4e5000) The buggy address belongs to the page: page:ffffea0007b93800 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c280 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x19a/0x380 mm/page_alloc.c:2171 get_page_from_freelist+0x550/0x8b0 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x2d6/0x740 mm/page_alloc.c:4855 alloc_slab_page+0x39/0x3e0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x460 mm/slub.c:1749 new_slab_objects mm/slub.c:2506 [inline] ___slab_alloc+0x330/0x4c0 mm/slub.c:2667 __slab_alloc mm/slub.c:2707 [inline] slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x1ee/0x2f0 mm/slub.c:3909 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x7e/0xf0 mm/util.c:564 kvmalloc include/linux/mm.h:758 [inline] kvmalloc_array include/linux/mm.h:776 [inline] nf_ct_alloc_hashtable+0x8e/0x1c0 net/netfilter/nf_conntrack_core.c:2303 nf_conntrack_expect_init+0xaa/0x110 net/netfilter/nf_conntrack_expect.c:712 nf_conntrack_init_start+0x2c9/0x470 net/netfilter/nf_conntrack_core.c:2472 nf_conntrack_standalone_init+0xc/0xf6 net/netfilter/nf_conntrack_standalone.c:1173 do_one_initcall+0x175/0x5d0 init/main.c:1205 do_initcall_level+0x101/0x256 init/main.c:1272 do_initcalls+0x4b/0x8c init/main.c:1288 kernel_init_freeable+0x21a/0x381 init/main.c:1469 page_owner free stack trace missing Memory state around the buggy address: ffff8881ee4e3f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881ee4e3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881ee4e4000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ee4e4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ee4e4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================