syzbot

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BUG: KASAN: use-after-free in usb_udc_uevent+0xb0/0x120 drivers/usb/gadget/udc/core.c:1765
Read of size 8 at addr ffff88810d894010 by task udevd/29216

CPU: 1 PID: 29216 Comm: udevd Not tainted 5.15.178-syzkaller-00260-g760764029c6d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1c0 lib/dump_stack.c:106
 print_address_description+0x87/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:444
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 usb_udc_uevent+0xb0/0x120 drivers/usb/gadget/udc/core.c:1765
 dev_uevent+0x4e9/0x6f0 drivers/base/core.c:2362
 uevent_show+0x1b4/0x330 drivers/base/core.c:2420
 dev_attr_show+0x56/0xd0 drivers/base/core.c:2120
 sysfs_kf_seq_show+0x265/0x3e0 fs/sysfs/file.c:61
 kernfs_seq_show+0x119/0x160 fs/kernfs/file.c:168
 seq_read_iter+0x430/0xd00 fs/seq_file.c:230
 kernfs_fop_read_iter+0x145/0x470 fs/kernfs/file.c:241
 call_read_iter include/linux/fs.h:2198 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0xa81/0xd40 fs/read_write.c:485
 ksys_read+0x199/0x2c0 fs/read_write.c:623
 __do_sys_read fs/read_write.c:633 [inline]
 __se_sys_read fs/read_write.c:631 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:631
 x64_sys_call+0x28/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f38d8c31b6a
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:00007ffc8a1153d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055d062440cf0 RCX: 00007f38d8c31b6a
RDX: 0000000000001000 RSI: 000055d06235b580 RDI: 0000000000000008
RBP: 000055d062440cf0 R08: 0000000000000008 R09: 0000000000000100
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffc8a1158b8 R15: 000000000000000a
 </TASK>

Allocated by task 4186:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 ____kasan_kmalloc+0xdb/0x110 mm/kasan/common.c:512
 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 kmem_cache_alloc_trace+0x11a/0x270 mm/slub.c:3269
 kmalloc include/linux/slab.h:603 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 dev_new drivers/usb/gadget/legacy/raw_gadget.c:191 [inline]
 raw_open+0x8b/0x3c0 drivers/usb/gadget/legacy/raw_gadget.c:387
 misc_open+0x30f/0x380 drivers/char/misc.c:141
 chrdev_open+0x4f7/0x620 fs/char_dev.c:414
 do_dentry_open+0x81c/0xfd0 fs/open.c:828
 vfs_open+0x73/0x80 fs/open.c:958
 do_open fs/namei.c:3608 [inline]
 path_openat+0x26f0/0x2f40 fs/namei.c:3742
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13f/0x820 fs/open.c:1234
 do_sys_open fs/open.c:1250 [inline]
 __do_sys_openat fs/open.c:1266 [inline]
 __se_sys_openat fs/open.c:1261 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1261
 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4185:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xbd/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3521 [inline]
 kfree+0xcc/0x270 mm/slub.c:4583
 dev_free drivers/usb/gadget/legacy/raw_gadget.c:227 [inline]
 kref_put+0x701/0x7c0 include/linux/kref.h:65
 raw_release+0x145/0x1e0 drivers/usb/gadget/legacy/raw_gadget.c:426
 __fput+0x228/0x8c0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x129/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xc48/0x2ca0 kernel/exit.c:880
 do_group_exit+0x141/0x310 kernel/exit.c:1002
 get_signal+0x7a3/0x1630 kernel/signal.c:2907
 arch_do_signal_or_restart+0xbd/0x1680 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa0/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x26/0x160 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88810d894000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 16 bytes inside of
 4096-byte region [ffff88810d894000, ffff88810d895000)
The buggy address belongs to the page:
page:ffffea0004362400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d890
head:ffffea0004362400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043380
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), pid 291, ts 23067125939, free_ts 23054256885
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4485
 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5780
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1932 [inline]
 new_slab+0x9a/0x4e0 mm/slub.c:1995
 ___slab_alloc+0x39e/0x830 mm/slub.c:3028
 __slab_alloc+0x4a/0x90 mm/slub.c:3115
 slab_alloc_node mm/slub.c:3206 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc_trace+0x147/0x270 mm/slub.c:3267
 kmalloc include/linux/slab.h:603 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 snmp6_alloc_dev net/ipv6/addrconf.c:359 [inline]
 ipv6_add_dev+0x5d3/0x1140 net/ipv6/addrconf.c:409
 addrconf_notify+0x593/0xdd0 net/ipv6/addrconf.c:3599
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:391
 call_netdevice_notifiers_info net/core/dev.c:2026 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2038 [inline]
 call_netdevice_notifiers+0x145/0x1b0 net/core/dev.c:2052
 register_netdevice+0x1035/0x1390 net/core/dev.c:10404
 veth_newlink+0x72e/0xe20 drivers/net/veth.c:1683
 __rtnl_newlink net/core/rtnetlink.c:3521 [inline]
 rtnl_newlink+0x14c7/0x2050 net/core/rtnetlink.c:3569
 rtnetlink_rcv_msg+0x951/0xc40 net/core/rtnetlink.c:5647
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1472 [inline]
 free_pcp_prepare mm/page_alloc.c:1544 [inline]
 free_unref_page_prepare+0x7c8/0x7d0 mm/page_alloc.c:3534
 free_unref_page+0xe8/0x750 mm/page_alloc.c:3616
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x61/0xf0 mm/page_alloc.c:5856
 __free_slab+0xec/0x1d0 mm/slub.c:2020
 free_slab mm/slub.c:2035 [inline]
 discard_slab mm/slub.c:2041 [inline]
 __unfreeze_partials+0x165/0x1a0 mm/slub.c:2527
 put_cpu_partial+0xc4/0x120 mm/slub.c:2607
 __slab_free+0x1c8/0x290 mm/slub.c:3390
 do_slab_free mm/slub.c:3509 [inline]
 ___cache_free+0x109/0x120 mm/slub.c:3530
 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x44/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3240 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc_trace+0xf9/0x270 mm/slub.c:3267
 kmalloc include/linux/slab.h:603 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 kobject_uevent_env+0x269/0x700 lib/kobject_uevent.c:539
 kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:657

Memory state around the buggy address:
 ffff88810d893f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810d893f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810d894000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88810d894080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810d894100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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