EXT4-fs error (device loop9): __ext4_get_inode_loc:4451: comm kworker/u4:1: Invalid inode table block 8463800222054970741 in block_group 0 ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:826 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 Read of size 4 at addr ffff88812cd29120 by task kworker/u4:1/9 CPU: 0 PID: 9 Comm: kworker/u4:1 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: writeback wb_workfn (flush-7:9) Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:826 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 ext4_ext_map_blocks+0x20b/0x5e00 fs/ext4/extents.c:4176 ext4_map_blocks+0x985/0x1bd0 fs/ext4/inode.c:676 mpage_map_one_extent fs/ext4/inode.c:2454 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2507 [inline] ext4_writepages+0x136a/0x2eb0 fs/ext4/inode.c:2875 do_writepages+0x128/0x280 mm/page-writeback.c:2380 __writeback_single_inode+0xd5/0xa20 fs/fs-writeback.c:1470 writeback_sb_inodes+0x8ca/0x1480 fs/fs-writeback.c:1733 wb_writeback+0x403/0xbe0 fs/fs-writeback.c:1908 wb_do_writeback fs/fs-writeback.c:2053 [inline] wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2094 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the page: page:ffffea0004b34a40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12cd29 flags: 0x4000000000000000() raw: 4000000000000000 dead000000000100 dead000000000122 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 1066, ts 47101296889, free_ts 47239801408 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384 __alloc_pages include/linux/gfp.h:544 [inline] __alloc_pages_node include/linux/gfp.h:557 [inline] alloc_pages_node include/linux/gfp.h:571 [inline] alloc_pages include/linux/gfp.h:590 [inline] shmem_alloc_page+0x1fd/0x380 mm/shmem.c:1580 shmem_alloc_and_acct_page+0x3b7/0x820 mm/shmem.c:1605 shmem_getpage_gfp+0x625/0x2120 mm/shmem.c:1918 shmem_getpage mm/shmem.c:161 [inline] shmem_write_begin+0xce/0x1b0 mm/shmem.c:2497 generic_perform_write+0x2ce/0x540 mm/filemap.c:3509 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3638 generic_file_write_iter+0xa9/0x1d0 mm/filemap.c:3670 __kernel_write+0x535/0x910 fs/read_write.c:550 dump_emit+0x246/0x370 fs/coredump.c:855 dump_user_range+0x6a/0x1a0 fs/coredump.c:908 elf_core_dump+0x2866/0x2cc0 fs/binfmt_elf.c:2290 do_coredump+0x1ba3/0x28e0 fs/coredump.c:817 get_signal+0xf23/0x12e0 kernel/signal.c:2779 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page_list+0x129/0x9c0 mm/page_alloc.c:3443 release_pages+0xe52/0xea0 mm/swap.c:1103 __pagevec_release+0x71/0xe0 mm/swap.c:1123 pagevec_release include/linux/pagevec.h:88 [inline] shmem_undo_range+0x74a/0x1810 mm/shmem.c:965 shmem_truncate_range mm/shmem.c:1069 [inline] shmem_evict_inode+0x210/0xa00 mm/shmem.c:1169 evict+0x4ae/0x930 fs/inode.c:612 iput_final fs/inode.c:1736 [inline] iput+0x638/0x7c0 fs/inode.c:1762 dentry_unlink_inode+0x2cf/0x380 fs/dcache.c:378 __dentry_kill+0x44f/0x650 fs/dcache.c:583 shrink_dentry_list+0x38e/0x500 fs/dcache.c:1146 shrink_dcache_parent+0xa9/0x270 fs/dcache.c:-1 do_one_tree+0x27/0x150 fs/dcache.c:1627 shrink_dcache_for_umount+0x6a/0x110 fs/dcache.c:1644 generic_shutdown_super+0x66/0x320 fs/super.c:447 kill_anon_super fs/super.c:1131 [inline] kill_litter_super+0x77/0xa0 fs/super.c:1140 Memory state around the buggy address: ffff88812cd29000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812cd29080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88812cd29100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88812cd29180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812cd29200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop9): ext4_map_blocks:742: inode #19: block 129065670028391: comm kworker/u4:1: lblock 0 mapped to illegal pblock 129065670028391 (length 16) EXT4-fs (loop9): Delayed block allocation failed for inode 19 at logical offset 0 with max blocks 16 with error 117 EXT4-fs (loop9): This should not happen!! Data will be lost EXT4-fs error (device loop9): __ext4_get_inode_loc:4451: comm kworker/u4:1: Invalid inode table block 8463800222054970741 in block_group 0 EXT4-fs error (device loop9): __ext4_get_inode_loc:4451: comm kworker/u4:1: Invalid inode table block 8463800222054970741 in block_group 0