================================================================== BUG: KASAN: use-after-free in strlen+0x58/0x70 lib/string.c:418 Read of size 1 at addr ffff88803e3033c4 by task syz-executor.1/26320 CPU: 0 PID: 26320 Comm: syz-executor.1 Not tainted 6.2.0-syzkaller-00081-g91bc559d8d3a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x163/0x4f0 mm/kasan/report.c:417 kasan_report+0x13a/0x170 mm/kasan/report.c:517 strlen+0x58/0x70 lib/string.c:418 set_de_name_and_namelen fs/reiserfs/namei.c:82 [inline] linear_search_in_dir_item fs/reiserfs/namei.c:262 [inline] reiserfs_find_entry+0x982/0x19b0 fs/reiserfs/namei.c:331 reiserfs_lookup+0x1ea/0x4b0 fs/reiserfs/namei.c:368 __lookup_slow+0x282/0x3e0 fs/namei.c:1686 lookup_one_len+0x18b/0x2d0 fs/namei.c:2712 reiserfs_lookup_privroot+0x89/0x1e0 fs/reiserfs/xattr.c:973 reiserfs_fill_super+0x21c1/0x2620 fs/reiserfs/super.c:2174 mount_bdev+0x271/0x3a0 fs/super.c:1372 legacy_get_tree+0xef/0x190 fs/fs_context.c:610 vfs_get_tree+0x8c/0x270 fs/super.c:1502 do_new_mount+0x28f/0xae0 fs/namespace.c:3031 do_mount fs/namespace.c:3374 [inline] __do_sys_mount fs/namespace.c:3583 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3560 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9243e8d62a Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9244b2df88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000001124 RCX: 00007f9243e8d62a RDX: 00000000200000c0 RSI: 0000000020000040 RDI: 00007f9244b2dfe0 RBP: 00007f9244b2e020 R08: 00007f9244b2e020 R09: 0000000000008008 R10: 0000000000008008 R11: 0000000000000202 R12: 00000000200000c0 R13: 0000000020000040 R14: 00007f9244b2dfe0 R15: 0000000020000300 The buggy address belongs to the physical page: page:ffffea0000f8c0c0 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x1 pfn:0x3e303 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0000cb3ec8 ffffea0000db30c8 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 26243, tgid 26242 (syz-executor.5), ts 1254498896834, free_ts 1255920761112 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x3449/0x35c0 mm/page_alloc.c:4283 __alloc_pages+0x291/0x7e0 mm/page_alloc.c:5549 __folio_alloc+0x13/0x30 mm/page_alloc.c:5581 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2248 shmem_alloc_folio mm/shmem.c:1569 [inline] shmem_alloc_and_acct_folio+0x596/0xd40 mm/shmem.c:1593 shmem_get_folio_gfp+0x1408/0x34a0 mm/shmem.c:1920 shmem_get_folio mm/shmem.c:2051 [inline] shmem_write_begin+0x172/0x4f0 mm/shmem.c:2544 generic_perform_write+0x300/0x5e0 mm/filemap.c:3773 __generic_file_write_iter+0x17a/0x400 mm/filemap.c:3901 generic_file_write_iter+0xaf/0x310 mm/filemap.c:3933 call_write_iter include/linux/fs.h:1849 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7b2/0xbb0 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare mm/page_alloc.c:1496 [inline] free_unref_page_prepare+0xf3a/0x1040 mm/page_alloc.c:3369 free_unref_page_list+0x6b1/0x950 mm/page_alloc.c:3510 release_pages+0x219e/0x2470 mm/swap.c:1046 __pagevec_release+0x84/0x100 mm/swap.c:1066 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x6b6/0x1dd0 mm/shmem.c:947 shmem_truncate_range mm/shmem.c:1042 [inline] shmem_evict_inode+0x258/0x9f0 mm/shmem.c:1151 evict+0x2a4/0x620 fs/inode.c:665 __dentry_kill+0x436/0x650 fs/dcache.c:607 dentry_kill+0xbb/0x290 dput+0x1d8/0x3f0 fs/dcache.c:913 __fput+0x5e4/0x890 fs/file_table.c:329 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x64/0x2e0 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff88803e303280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803e303300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88803e303380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803e303400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803e303480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================