================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:646 [inline] BUG: KASAN: slab-use-after-free in string+0x394/0x3d0 lib/vsprintf.c:728 Read of size 1 at addr ffff88801d7bc900 by task udevd/4502 CPU: 0 PID: 4502 Comm: udevd Not tainted 6.7.0-syzkaller-12377-g9d1694dc91ce #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 string_nocheck lib/vsprintf.c:646 [inline] string+0x394/0x3d0 lib/vsprintf.c:728 vsnprintf+0xc5f/0x1870 lib/vsprintf.c:2824 add_uevent_var+0x17c/0x3a0 lib/kobject_uevent.c:665 dev_uevent+0x18b/0x760 drivers/base/core.c:2576 uevent_show+0x1bf/0x380 drivers/base/core.c:2647 dev_attr_show+0x4f/0xd0 drivers/base/core.c:2350 sysfs_kf_seq_show+0x23e/0x400 fs/sysfs/file.c:59 seq_read_iter+0x4e5/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x410/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2079 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x6bb/0xb70 fs/read_write.c:476 ksys_read+0x12f/0x250 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fa60938cb6a 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:00007fff9458bc28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055ba21ff51c0 RCX: 00007fa60938cb6a RDX: 0000000000001000 RSI: 000055ba21fb7a60 RDI: 000000000000000c RBP: 000055ba21ff51c0 R08: 000000000000000c R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fff9458c108 R15: 000000000000000a Allocated by task 23991: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:372 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:389 kmalloc include/linux/slab.h:590 [inline] raw_ioctl_init+0x163/0x840 drivers/usb/gadget/legacy/raw_gadget.c:509 raw_ioctl+0x9d9/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1303 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Freed by task 23996: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x124/0x360 mm/slub.c:4409 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:211 kref_put include/linux/kref.h:65 [inline] raw_release+0x184/0x2e0 drivers/usb/gadget/legacy/raw_gadget.c:473 __fput+0x270/0xb70 fs/file_table.c:376 task_work_run+0x14d/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa8a/0x2ad0 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 get_signal+0x23b5/0x2790 kernel/signal.c:2893 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x156/0x2b0 kernel/entry/common.c:212 do_syscall_64+0xe0/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff88801d7bc900 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of freed 32-byte region [ffff88801d7bc900, ffff88801d7bc920) The buggy address belongs to the physical page: page:ffffea000075ef00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d7bc flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888013041500 ffffea0000763080 dead000000000004 raw: 0000000000000000 0000000000200020 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 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 7548, tgid 7548 (udevd), ts 1877379857001, free_ts 1877092703615 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311 __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2354 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2407 ___slab_alloc+0x4af/0x19a0 mm/slub.c:3540 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3625 __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] __do_kmalloc_node mm/slub.c:3980 [inline] __kmalloc_node_track_caller+0x35b/0x460 mm/slub.c:4001 kmemdup+0x29/0x60 mm/util.c:131 kmemdup include/linux/fortify-string.h:761 [inline] sidtab_sid2str_get+0x17a/0x680 security/selinux/ss/sidtab.c:620 sidtab_entry_to_string+0x33/0x100 security/selinux/ss/services.c:1268 security_sid_to_context_core+0x358/0x630 security/selinux/ss/services.c:1371 selinux_inode_init_security+0x4f1/0x710 security/selinux/hooks.c:2949 security_inode_init_security+0x1a3/0x3b0 security/security.c:1732 shmem_mknod+0xe5/0x240 mm/shmem.c:3249 lookup_open.isra.0+0x1095/0x13b0 fs/namei.c:3496 open_last_lookups fs/namei.c:3565 [inline] path_openat+0x931/0x2990 fs/namei.c:3795 page last free pid 17325 tgid 17324 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x51f/0xb10 mm/page_alloc.c:2346 free_unref_page_list+0xe6/0xb40 mm/page_alloc.c:2532 release_pages+0x32a/0x14f0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu mm/mmu_gather.c:300 [inline] tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392 exit_mmap+0x3da/0xb50 mm/mmap.c:3290 __mmput+0x12a/0x4d0 kernel/fork.c:1343 mmput+0x62/0x70 kernel/fork.c:1365 exit_mm kernel/exit.c:569 [inline] do_exit+0x9a5/0x2ad0 kernel/exit.c:858 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 get_signal+0x23b5/0x2790 kernel/signal.c:2893 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x156/0x2b0 kernel/entry/common.c:212 do_syscall_64+0xe0/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff88801d7bc800: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff88801d7bc880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801d7bc900: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88801d7bc980: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff88801d7bca00: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================