================================================================== BUG: KASAN: slab-out-of-bounds in kernfs_name_compare fs/kernfs/dir.c:326 [inline] BUG: KASAN: slab-out-of-bounds in kernfs_find_ns+0x473/0x510 fs/kernfs/dir.c:827 Read of size 4 at addr ffff88802540a8a0 by task syz.2.2430/15107 CPU: 1 PID: 15107 Comm: syz.2.2430 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 kernfs_name_compare fs/kernfs/dir.c:326 [inline] kernfs_find_ns+0x473/0x510 fs/kernfs/dir.c:827 kernfs_remove_by_name_ns+0x37/0x100 fs/kernfs/dir.c:1563 remove_bind_files drivers/base/bus.c:550 [inline] bus_remove_driver+0x89/0x230 drivers/base/bus.c:674 comedi_device_detach_locked+0x16e/0x710 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:844 [inline] comedi_unlocked_ioctl+0xd0b/0x1050 drivers/comedi/comedi_fops.c:2173 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7feb22792fc9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007feb209b8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007feb229ea180 RCX: 00007feb22792fc9 RDX: 0000000000000000 RSI: 0000000040946400 RDI: 0000000000000007 RBP: 00007feb22815f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb229ea218 R14: 00007feb229ea180 R15: 00007ffedb7ba018 Allocated by task 12361: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] uevent_net_init+0xc3/0x2b0 lib/kobject_uevent.c:781 ops_init+0x357/0x600 net/core/net_namespace.c:138 setup_net+0x38d/0x9f0 net/core/net_namespace.c:333 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4bc/0x890 kernel/fork.c:3175 __do_sys_unshare kernel/fork.c:3249 [inline] __se_sys_unshare kernel/fork.c:3247 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3247 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88802540a880 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes to the right of 32-byte region [ffff88802540a880, ffff88802540a8a0) The buggy address belongs to the page: page:ffffea0000950280 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2540a flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff888016841500 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4472, ts 866817845718, free_ts 866778079755 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x27e/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x5cd/0x610 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x183/0x360 security/tomoyo/file.c:771 security_file_open+0x5e/0xa0 security/security.c:1668 do_dentry_open+0x322/0xf80 fs/open.c:813 do_open fs/namei.c:3616 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3750 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 tlb_batch_list_free mm/mmu_gather.c:61 [inline] tlb_finish_mmu+0x236/0x2e0 mm/mmu_gather.c:341 exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88802540a780: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88802540a800: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88802540a880: 00 00 00 fc fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88802540a900: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88802540a980: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc ==================================================================