comedi comedi3: c6xdigio: I/O port conflict (0x4f27,3) ================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:522 Read of size 8 at addr ffff88803bdd0030 by task syz.7.1157/10296 CPU: 0 UID: 0 PID: 10296 Comm: syz.7.1157 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 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+0x13d/0x9e0 drivers/comedi/drivers.c:207 comedi_device_attach+0x43d/0x900 drivers/comedi/drivers.c:1003 do_devconfig_ioctl+0x1a7/0x580 drivers/comedi/comedi_fops.c:855 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893 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: 0033:0x7f499d38e9a9 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:00007f499b1f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f499d5b6080 RCX: 00007f499d38e9a9 RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000007 RBP: 00007f499d410d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f499d5b6080 R15: 00007ffe4e4d0a38 Allocated by task 10145: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_node_noprof+0x21e/0x500 mm/slub.c:4334 kmalloc_array_node_noprof include/linux/slab.h:1020 [inline] alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:1992 account_slab mm/slub.c:2578 [inline] allocate_slab mm/slub.c:2638 [inline] new_slab+0x283/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __kmem_cache_alloc_bulk mm/slub.c:5294 [inline] kmem_cache_alloc_bulk_noprof+0x24e/0xbc0 mm/slub.c:5366 __io_alloc_req_refill+0x98/0x500 io_uring/io_uring.c:972 io_alloc_req io_uring/io_uring.h:447 [inline] io_submit_sqes+0xde5/0x2580 io_uring/io_uring.c:2326 __io_sq_thread io_uring/sqpoll.c:198 [inline] io_sq_thread+0x971/0x1c60 io_uring/sqpoll.c:322 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 10274: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 free_slab_obj_exts mm/slub.c:2047 [inline] unaccount_slab mm/slub.c:2592 [inline] __free_slab+0x117/0x170 mm/slub.c:2687 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0x79c/0x14e0 kernel/rcu/tree.c:2832 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 The buggy address belongs to the object at ffff88803bdd0000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of freed 256-byte region [ffff88803bdd0000, ffff88803bdd0100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3bdd0 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842b40 ffffea0000c84380 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842b40 ffffea0000c84380 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000ef7401 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 5366, tgid 5366 (udevd), ts 54376367077, free_ts 54373536785 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] inode_doinit_use_xattr+0x54/0x410 security/selinux/hooks.c:1366 inode_doinit_with_dentry+0x10c8/0x12e0 security/selinux/hooks.c:1560 selinux_d_instantiate+0x26/0x30 security/selinux/hooks.c:6495 security_d_instantiate+0x142/0x1a0 security/security.c:4079 d_splice_alias+0x93/0xf80 fs/dcache.c:2997 kernfs_iop_lookup+0x23f/0x2d0 fs/kernfs/dir.c:1251 __lookup_slow+0x251/0x460 fs/namei.c:1817 lookup_slow fs/namei.c:1834 [inline] walk_component+0x353/0x5b0 fs/namei.c:2138 page last free pid 28 tgid 28 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0x79c/0x14e0 kernel/rcu/tree.c:2832 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 run_ksoftirqd kernel/softirq.c:968 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960 smpboot_thread_fn+0x3f4/0xae0 kernel/smpboot.c:164 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88803bdcff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88803bdcff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88803bdd0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803bdd0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803bdd0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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