================================================================== BUG: KASAN: use-after-free in __kernfs_remove+0x9dd/0xb30 Read of size 2 at addr ffff88800e180438 by task syz-executor.0/15074 CPU: 1 PID: 15074 Comm: syz-executor.0 Not tainted 6.0.0-rc3-next-20220829 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x8b/0xb3 print_report.cold+0x5e/0x5e5 kasan_report+0xb1/0x1c0 __kernfs_remove+0x9dd/0xb30 kernfs_remove_by_name_ns+0xa8/0x110 sysfs_slab_add+0x142/0x1f0 __kmem_cache_create+0x49d/0x600 kmem_cache_create_usercopy+0x1fd/0x2e0 p9_client_create+0xc85/0x1050 v9fs_session_init+0x1dd/0x1670 v9fs_mount+0xb9/0xbd0 legacy_get_tree+0x105/0x220 vfs_get_tree+0x8e/0x300 path_mount+0x1310/0x1e20 __x64_sys_mount+0x282/0x300 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f56402a9b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f563d81f188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f56403bcf60 RCX: 00007f56402a9b19 RDX: 0000000020000080 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00007f5640303f6d R08: 00000000200003c0 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeb234f4df R14: 00007f563d81f300 R15: 0000000000022000 Allocated by task 15068: kasan_save_stack+0x1e/0x40 __kasan_slab_alloc+0x66/0x80 kmem_cache_alloc+0x1b1/0x3e0 __kernfs_new_node+0xd4/0x8c0 kernfs_create_dir_ns+0x9c/0x230 sysfs_create_dir_ns+0x127/0x290 kobject_add_internal+0x24c/0x8e0 kobject_init_and_add+0x101/0x160 sysfs_slab_add+0x165/0x1f0 __kmem_cache_create+0x49d/0x600 kmem_cache_create_usercopy+0x1fd/0x2e0 p9_client_create+0xc85/0x1050 v9fs_session_init+0x1dd/0x1670 v9fs_mount+0xb9/0xbd0 legacy_get_tree+0x105/0x220 vfs_get_tree+0x8e/0x300 path_mount+0x1310/0x1e20 __x64_sys_mount+0x282/0x300 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 15074: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free+0x108/0x190 kmem_cache_free+0xf7/0x610 kernfs_put.part.0+0x2c7/0x540 kernfs_put+0x42/0x50 __kernfs_remove+0x7d4/0xb30 kernfs_remove_by_name_ns+0xa8/0x110 sysfs_slab_add+0x142/0x1f0 __kmem_cache_create+0x49d/0x600 kmem_cache_create_usercopy+0x1fd/0x2e0 p9_client_create+0xc85/0x1050 v9fs_session_init+0x1dd/0x1670 v9fs_mount+0xb9/0xbd0 legacy_get_tree+0x105/0x220 vfs_get_tree+0x8e/0x300 path_mount+0x1310/0x1e20 __x64_sys_mount+0x282/0x300 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88800e1803a0 which belongs to the cache kernfs_node_cache of size 168 The buggy address is located 152 bytes inside of 168-byte region [ffff88800e1803a0, ffff88800e180448) The buggy address belongs to the physical page: page:000000007ddf89f3 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xe180 flags: 0x100000000000200(slab|node=0|zone=1) raw: 0100000000000200 ffffea0000391580 dead00000000000a ffff88800847b8c0 raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88800e180300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88800e180380: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb >ffff88800e180400: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc ^ ffff88800e180480: fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88800e180500: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ================================================================== tmpfs: Unknown parameter 'øÒ{¸½<üLùÉx5ëP%{§ÿ#‘£' tmpfs: Unknown parameter 'øÒ{¸½<üLùÉx5ëP%{§ÿ#‘£' tmpfs: Unknown parameter 'øÒ{¸½<üLùÉx5ëP%{§ÿ#‘£'