comedi comedi3: c6xdigio: I/O port conflict (0x7,3) ================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:522 Read of size 8 at addr ffff88807b8e7030 by task syz.7.4553/24042 CPU: 0 UID: 0 PID: 24042 Comm: syz.7.4553 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:522 sysfs_remove_file include/linux/sysfs.h:777 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:605 [inline] bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207 comedi_device_detach+0x67/0xb0 drivers/comedi/drivers.c:215 comedi_device_attach+0x43d/0x900 drivers/comedi/drivers.c:1011 do_devconfig_ioctl+0x1b1/0x710 drivers/comedi/comedi_fops.c:872 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf7b38ebe9 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:00007fbf795f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbf7b5c6090 RCX: 00007fbf7b38ebe9 RDX: 0000200000000080 RSI: 0000000040946400 RDI: 0000000000000007 RBP: 00007fbf7b411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbf7b5c6128 R14: 00007fbf7b5c6090 R15: 00007ffd4518f5e8 Allocated by task 23456: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] security_inode_init_security+0x13f/0x390 security/security.c:1829 shmem_symlink+0x135/0x9f0 mm/shmem.c:4163 vfs_symlink fs/namei.c:4730 [inline] vfs_symlink+0x403/0x680 fs/namei.c:4714 do_symlinkat+0x261/0x310 fs/namei.c:4756 __do_sys_symlinkat fs/namei.c:4772 [inline] __se_sys_symlinkat fs/namei.c:4769 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4769 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23456: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4894 security_inode_init_security+0x2eb/0x390 security/security.c:1856 shmem_symlink+0x135/0x9f0 mm/shmem.c:4163 vfs_symlink fs/namei.c:4730 [inline] vfs_symlink+0x403/0x680 fs/namei.c:4714 do_symlinkat+0x261/0x310 fs/namei.c:4756 __do_sys_symlinkat fs/namei.c:4772 [inline] __se_sys_symlinkat fs/namei.c:4769 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4769 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807b8e7000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of freed 256-byte region [ffff88807b8e7000, ffff88807b8e7100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807b8e6000 pfn:0x7b8e6 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b841b40 ffffea00016b0510 ffffea0001e52990 raw: ffff88807b8e6000 0000000000100008 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b841b40 ffffea00016b0510 ffffea0001e52990 head: ffff88807b8e6000 0000000000100008 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0001ee3981 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5836, tgid 5836 (udevd), ts 66814822192, free_ts 66803775118 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] security_inode_init_security+0x13f/0x390 security/security.c:1829 shmem_mknod+0x22e/0x450 mm/shmem.c:3912 lookup_open.isra.0+0x11d0/0x1580 fs/namei.c:3708 open_last_lookups fs/namei.c:3807 [inline] path_openat+0x893/0x2cb0 fs/namei.c:4043 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 page last free pid 5220 tgid 5220 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 discard_slab mm/slub.c:2758 [inline] __put_partials+0x165/0x1c0 mm/slub.c:3223 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:322 getname include/linux/fs.h:2918 [inline] do_sys_openat2+0xb8/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807b8e6f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807b8e6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807b8e7000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807b8e7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b8e7100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================