EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /root/syzkaller-testdir3752269474/syzkaller.3WWk1h/56/file1 supports timestamps until 2038-01-19 (0x7fffffff) ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:837 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953 Read of size 4 at addr ffff88803bf92a88 by task syz-executor.0/7503 CPU: 1 PID: 7503 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-00055-g9ed22ae6be81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 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:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x175/0x1b0 mm/kasan/report.c:588 ext4_ext_binsearch fs/ext4/extents.c:837 [inline] ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953 ext4_ext_map_blocks+0x2cb/0x7150 fs/ext4/extents.c:4101 ext4_map_blocks+0xa2f/0x1cb0 fs/ext4/inode.c:621 mpage_map_one_extent fs/ext4/inode.c:2159 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2212 [inline] ext4_do_writepages+0x15e7/0x3c90 fs/ext4/inode.c:2675 ext4_writepages+0x203/0x3e0 fs/ext4/inode.c:2764 do_writepages+0x3a6/0x670 mm/page-writeback.c:2553 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] file_write_and_wait_range+0x20f/0x300 mm/filemap.c:781 generic_buffers_fsync_noflush+0x73/0x170 fs/buffer.c:609 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x3ee/0xb30 fs/ext4/fsync.c:151 generic_write_sync include/linux/fs.h:2584 [inline] ext4_buffered_write_iter+0x286/0x350 fs/ext4/file.c:305 ext4_file_write_iter+0x1d3/0x1ad0 fs/ext4/file.c:717 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x782/0xaf0 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 RIP: 0033:0x7f2514a7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f25158120c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2514b9bf80 RCX: 00007f2514a7cae9 RDX: 0000000000000020 RSI: 0000000020002c40 RDI: 0000000000000004 RBP: 00007f2514ac847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f2514b9bf80 R15: 00007ffd874e6fc8 The buggy address belongs to the physical page: page:ffffea0000efe480 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x3bf92 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000000 ffffea0000efe4c8 ffffea0000ecf148 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 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 7425, tgid 7420 (syz-executor.2), ts 286514261080, free_ts 288763340418 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426 __folio_alloc+0x13/0x30 mm/page_alloc.c:4458 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2259 shmem_alloc_folio mm/shmem.c:1658 [inline] shmem_alloc_and_acct_folio+0x438/0x9b0 mm/shmem.c:1683 shmem_get_folio_gfp+0xca4/0x2b60 mm/shmem.c:2020 shmem_get_folio mm/shmem.c:2143 [inline] shmem_write_begin+0x170/0x300 mm/shmem.c:2688 generic_perform_write+0x31b/0x630 mm/filemap.c:3969 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2865 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x782/0xaf0 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:1136 [inline] free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2451 release_pages+0x2113/0x23f0 mm/swap.c:1042 __folio_batch_release+0x84/0x100 mm/swap.c:1062 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x6ad/0x19c0 mm/shmem.c:1022 shmem_truncate_range mm/shmem.c:1114 [inline] shmem_evict_inode+0x29e/0xa80 mm/shmem.c:1243 evict+0x2a4/0x620 fs/inode.c:664 __dentry_kill+0x436/0x650 fs/dcache.c:607 dentry_kill+0xbb/0x290 dput+0x21e/0x470 fs/dcache.c:913 __fput+0x60d/0x910 fs/file_table.c:392 task_work_run+0x24a/0x300 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff88803bf92980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803bf92a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88803bf92a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803bf92b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803bf92b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================