================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:644 [inline] BUG: KASAN: use-after-free in string+0x235/0x2d0 lib/vsprintf.c:726 Read of size 1 at addr ffff8880628b7680 by task udevd/4421 CPU: 0 PID: 4421 Comm: udevd Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07 #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+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:306 print_report+0x107/0x220 mm/kasan/report.c:417 kasan_report+0x139/0x170 mm/kasan/report.c:517 string_nocheck lib/vsprintf.c:644 [inline] string+0x235/0x2d0 lib/vsprintf.c:726 vsnprintf+0x11c0/0x1cb0 lib/vsprintf.c:2796 add_uevent_var+0x1bf/0x440 lib/kobject_uevent.c:665 dev_uevent+0x3f0/0x910 drivers/base/core.c:2422 uevent_show+0x1a0/0x310 drivers/base/core.c:2493 dev_attr_show+0x50/0xc0 drivers/base/core.c:2196 sysfs_kf_seq_show+0x324/0x4a0 fs/sysfs/file.c:59 seq_read_iter+0x43a/0xd30 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2180 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x7cf/0xbc0 fs/read_write.c:470 ksys_read+0x19b/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9515d258fe 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:00007ffdc9c15478 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055cdc5e703e0 RCX: 00007f9515d258fe RDX: 0000000000001000 RSI: 000055cdc5ea96a0 RDI: 000000000000000c RBP: 00007f9515df2380 R08: 000000000000000c R09: 00007f9515df5a60 R10: 0000000000000004 R11: 0000000000000246 R12: 000055cdc5e703e0 R13: 0000000000000d68 R14: 00007f9515df1780 R15: 0000000000000d68 Allocated by task 25765: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] raw_ioctl_init+0x1bb/0x750 drivers/usb/gadget/legacy/raw_gadget.c:460 raw_ioctl+0x2a2/0xc20 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+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 25765: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:518 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x71/0x110 mm/slub.c:3800 dev_free drivers/usb/gadget/legacy/raw_gadget.c:210 [inline] kref_put+0xb5/0x7d0 include/linux/kref.h:65 raw_release+0x130/0x1e0 drivers/usb/gadget/legacy/raw_gadget.c:424 __fput+0x3ba/0x880 fs/file_table.c:320 task_work_run+0x243/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x644/0x2150 kernel/exit.c:867 do_group_exit+0x1fd/0x2b0 kernel/exit.c:1012 get_signal+0x1755/0x1820 kernel/signal.c:2859 arch_do_signal_or_restart+0x8d/0x5f0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x74/0x160 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880628b7680 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880628b7680, ffff8880628b76a0) The buggy address belongs to the physical page: page:ffffea00018a2dc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x628b7 anon flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff888012841500 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000400040 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 5086, tgid 5086 (syz-executor.2), ts 173363354162, free_ts 173359507739 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4283 __alloc_pages+0x259/0x560 mm/page_alloc.c:5549 alloc_slab_page+0xbd/0x190 mm/slub.c:1851 allocate_slab+0x5e/0x3c0 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0x7f4/0xeb0 mm/slub.c:3193 __slab_alloc mm/slub.c:3292 [inline] __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x25b/0x340 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x9e/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x5ae/0x5f0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1fe/0x7d0 security/tomoyo/file.c:723 security_file_ioctl+0x55/0xb0 security/security.c:1624 __do_sys_ioctl fs/ioctl.c:864 [inline] __se_sys_ioctl+0x48/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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+0x751/0x780 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x19/0x4c0 mm/page_alloc.c:3464 discard_slab mm/slub.c:2098 [inline] __unfreeze_partials+0x1a5/0x1e0 mm/slub.c:2637 put_cpu_partial+0x116/0x180 mm/slub.c:2713 qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 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/slub.c:3452 [inline] kmem_cache_alloc_node+0x1dc/0x390 mm/slub.c:3497 __alloc_skb+0xd7/0x2c0 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+0x774/0xcd0 net/netlink/af_netlink.c:1907 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] __sys_sendto+0x46d/0x5f0 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2125 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880628b7580: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ffff8880628b7600: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc >ffff8880628b7680: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff8880628b7700: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8880628b7780: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ==================================================================