================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:510 Read of size 8 at addr ffff88804b9ebc30 by task syz.8.6152/29371 CPU: 1 UID: 0 PID: 29371 Comm: syz.8.6152 Not tainted syzkaller #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:510 sysfs_remove_file include/linux/sysfs.h:770 [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 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848 comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2178 comedi_compat_ioctl+0x1d0/0x990 drivers/comedi/comedi_fops.c:3249 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f77579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f546655c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000000000d RCX: 0000000040946400 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 28738: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5642 [inline] __kmalloc_node_noprof+0x347/0x8a0 mm/slub.c:5648 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline] alloc_slab_obj_exts+0x43/0xf0 mm/slub.c:2123 account_slab mm/slub.c:3182 [inline] allocate_slab mm/slub.c:3247 [inline] new_slab+0x283/0x360 mm/slub.c:3282 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651 __kmem_cache_alloc_bulk+0x225/0x770 mm/slub.c:7394 kmem_cache_alloc_bulk_noprof+0x23d/0x5a0 mm/slub.c:7474 __io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1056 io_alloc_req io_uring/io_uring.h:543 [inline] io_submit_sqes+0xe07/0x2710 io_uring/io_uring.c:2436 __io_sq_thread io_uring/sqpoll.c:232 [inline] io_sq_thread+0x9b2/0x1e10 io_uring/sqpoll.c:344 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 28: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6837 free_slab_obj_exts mm/slub.c:2203 [inline] unaccount_slab mm/slub.c:3196 [inline] __free_slab+0x12f/0x180 mm/slub.c:3296 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x1530 kernel/rcu/tree.c:2861 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1063 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88804b9ebc00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of freed 256-byte region [ffff88804b9ebc00, ffff88804b9ebd00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804b9eb000 pfn:0x4b9ea head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000240 ffff88801b442b40 ffffea00014e9b90 ffffea0001405e90 raw: ffff88804b9eb000 0000000000100006 00000000f5000000 0000000000000000 head: 04fff00000000240 ffff88801b442b40 ffffea00014e9b90 ffffea0001405e90 head: ffff88804b9eb000 0000000000100006 00000000f5000000 0000000000000000 head: 04fff00000000001 ffffea00012e7a81 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 7392, tgid 7391 (syz.1.331), ts 127303722900, free_ts 109090480818 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_slab_page mm/slub.c:3057 [inline] allocate_slab mm/slub.c:3228 [inline] new_slab+0xa5/0x360 mm/slub.c:3282 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4770 __slab_alloc_node mm/slub.c:4846 [inline] slab_alloc_node mm/slub.c:5268 [inline] __do_kmalloc_node mm/slub.c:5641 [inline] __kmalloc_node_noprof+0x4dd/0x8a0 mm/slub.c:5648 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline] alloc_slab_obj_exts+0x43/0xf0 mm/slub.c:2123 account_slab mm/slub.c:3182 [inline] allocate_slab mm/slub.c:3247 [inline] new_slab+0x283/0x360 mm/slub.c:3282 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651 __kmem_cache_alloc_bulk+0x225/0x770 mm/slub.c:7394 kmem_cache_alloc_bulk_noprof+0x23d/0x5a0 mm/slub.c:7474 __io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1056 io_alloc_req io_uring/io_uring.h:543 [inline] io_submit_sqes+0xe07/0x2710 io_uring/io_uring.c:2436 __do_sys_io_uring_enter+0xd69/0x1630 io_uring/io_uring.c:3514 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 page last free pid 45 tgid 45 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 __folio_put+0x329/0x450 mm/swap.c:112 folio_put include/linux/mm.h:1425 [inline] migrate_folio_done+0x236/0x2c0 mm/migrate.c:1190 migrate_folio_move mm/migrate.c:1404 [inline] migrate_folios_move mm/migrate.c:1713 [inline] migrate_pages_batch+0x1ca0/0x3bb0 mm/migrate.c:1969 migrate_pages_sync+0x12d/0x8a0 mm/migrate.c:1999 migrate_pages+0x1b5f/0x23a0 mm/migrate.c:2108 compact_zone+0x2018/0x4750 mm/compaction.c:2647 compact_node+0x1a3/0x2c0 mm/compaction.c:2916 kcompactd+0x765/0xeb0 mm/compaction.c:3214 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88804b9ebb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804b9ebb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804b9ebc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804b9ebc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804b9ebd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi