================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x63/0x70 fs/sysfs/file.c:510 Read of size 8 at addr ffff888055698030 by task syz.0.1614/11534 CPU: 1 UID: 0 PID: 11534 Comm: syz.0.1614 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 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7ed378f6c9 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:00007f7ed4657038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7ed39e5fa0 RCX: 00007f7ed378f6c9 RDX: 0000000000000000 RSI: 0000000040946400 RDI: 0000000000000004 RBP: 00007f7ed3811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7ed39e6038 R14: 00007f7ed39e5fa0 R15: 00007ffe63c41478 Allocated by task 6724: 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 kmalloc_noprof include/linux/slab.h:957 [inline] inode_doinit_use_xattr+0x54/0x410 security/selinux/hooks.c:1370 inode_doinit_with_dentry+0x10c8/0x12e0 security/selinux/hooks.c:1564 selinux_d_instantiate+0x26/0x30 security/selinux/hooks.c:6523 security_d_instantiate+0x142/0x1a0 security/security.c:4148 d_splice_alias_ops+0x92/0x840 fs/dcache.c:3001 kernfs_iop_lookup+0x23f/0x2d0 fs/kernfs/dir.c:1251 __lookup_slow+0x251/0x460 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x353/0x5b0 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x142/0x6d0 fs/namei.c:2676 filename_lookup+0x224/0x5f0 fs/namei.c:2705 vfs_statx+0x101/0x3f0 fs/stat.c:353 vfs_fstatat+0x7b/0xf0 fs/stat.c:375 __do_sys_newfstatat+0x97/0x120 fs/stat.c:542 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6724: 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:6634 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6841 inode_doinit_use_xattr+0x1da/0x410 security/selinux/hooks.c:1394 inode_doinit_with_dentry+0x10c8/0x12e0 security/selinux/hooks.c:1564 selinux_d_instantiate+0x26/0x30 security/selinux/hooks.c:6523 security_d_instantiate+0x142/0x1a0 security/security.c:4148 d_splice_alias_ops+0x92/0x840 fs/dcache.c:3001 kernfs_iop_lookup+0x23f/0x2d0 fs/kernfs/dir.c:1251 __lookup_slow+0x251/0x460 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x353/0x5b0 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x142/0x6d0 fs/namei.c:2676 filename_lookup+0x224/0x5f0 fs/namei.c:2705 vfs_statx+0x101/0x3f0 fs/stat.c:353 vfs_fstatat+0x7b/0xf0 fs/stat.c:375 __do_sys_newfstatat+0x97/0x120 fs/stat.c:542 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888055698000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of freed 256-byte region [ffff888055698000, ffff888055698100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888055698000 pfn:0x55698 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 ffff88801b442b40 ffffea0000e5fa90 ffffea0000b8e610 raw: ffff888055698000 000000000010000e 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b442b40 ffffea0000e5fa90 ffffea0000b8e610 head: ffff888055698000 000000000010000e 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea000155a601 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 7096, tgid 7094 (syz.0.344), ts 74537056149, free_ts 73507053754 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+0xd79/0x1a50 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5272 [inline] __do_kmalloc_node mm/slub.c:5645 [inline] __kmalloc_node_noprof+0x4dd/0x8a0 mm/slub.c:5652 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+0xd79/0x1a50 mm/slub.c:4651 __kmem_cache_alloc_bulk+0x225/0x770 mm/slub.c:7398 kmem_cache_alloc_bulk_noprof+0x23d/0x5a0 mm/slub.c:7478 __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_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 page last free pid 5342 tgid 5342 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 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:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4974 [inline] slab_alloc_node mm/slub.c:5284 [inline] kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5291 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:345 getname include/linux/fs.h:2922 [inline] do_sys_openat2+0xb8/0x1d0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888055697f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888055697f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888055698000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055698080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055698100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================