EXT4-fs (loop4): failed to convert unwritten extents to written extents -- potential data loss! (inode 19, error -117) ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 Read of size 4 at addr ffff888126310784 by task kworker/u4:1/10 CPU: 1 PID: 10 Comm: kworker/u4:1 Not tainted 5.15.185-syzkaller-1080583-ge678c93d43cc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:827 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 ext4_ext_map_blocks+0x1de/0x6270 fs/ext4/extents.c:4165 ext4_map_blocks+0x97b/0x1b20 fs/ext4/inode.c:674 ext4_convert_unwritten_extents+0x2a2/0x5c0 fs/ext4/extents.c:4867 ext4_convert_unwritten_io_end_vec+0x103/0x180 fs/ext4/extents.c:4906 ext4_end_io_end fs/ext4/page-io.c:186 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline] ext4_end_io_rsv_work+0x2b9/0x600 fs/ext4/page-io.c:273 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the page: page:ffffea000498c400 refcount:1 mapcount:1 mapping:0000000000000000 index:0x55fb5caef pfn:0x126310 memcg:ffff88810024c000 anon flags: 0x4000000000080014(uptodate|lru|swapbacked|zone=1) raw: 4000000000080014 ffffea000498c248 ffffea00045ad7c8 ffff88811ac4f5c1 raw: 000000055fb5caef 0000000000000000 0000000100000000 ffff88810024c000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x100cca(GFP_HIGHUSER_MOVABLE), pid 358, ts 49004775747, free_ts 49003266431 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5789 __alloc_pages_node include/linux/gfp.h:591 [inline] alloc_pages_node include/linux/gfp.h:605 [inline] alloc_pages include/linux/gfp.h:618 [inline] wp_page_copy+0x20f/0x18f0 mm/memory.c:3225 do_wp_page+0x731/0xc90 mm/memory.c:-1 handle_pte_fault+0x73c/0x2680 mm/memory.c:4931 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1a6d/0x1d50 mm/memory.c:5332 handle_mm_fault include/linux/mm.h:1836 [inline] do_user_addr_fault+0x841/0x1180 arch/x86/mm/fault.c:1418 handle_page_fault arch/x86/mm/fault.c:1509 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1565 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page_list+0x134/0x9d0 mm/page_alloc.c:3671 release_pages+0x1076/0x10d0 mm/swap.c:1009 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x175/0x300 mm/mmu_gather.c:338 unmap_region+0x315/0x360 mm/mmap.c:2680 __do_munmap+0xa0e/0xfe0 mm/mmap.c:2913 __vm_munmap+0x15b/0x2a0 mm/mmap.c:2966 __do_sys_munmap mm/mmap.c:2992 [inline] __se_sys_munmap mm/mmap.c:2988 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:2988 x64_sys_call+0xc9/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888126310680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888126310700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888126310780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888126310800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888126310880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== EXT4-fs error (device loop4): ext4_map_blocks:740: inode #19: block 135748084778070: comm kworker/u4:1: lblock 13 mapped to illegal pblock 135748084778070 (length 1) EXT4-fs warning (device loop4): ext4_convert_unwritten_extents:4874: inode #19: block 13: len 1: ext4_ext_map_blocks returned -117 EXT4-fs error (device loop4): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop4) in ext4_reserve_inode_write:5866: Corrupt filesystem EXT4-fs error (device loop4): ext4_convert_unwritten_extents:4875: inode #19: comm kworker/u4:1: mark_inode_dirty error EXT4-fs (loop4): failed to convert unwritten extents to written extents -- potential data loss! (inode 19, error -117) EXT4-fs error (device loop2): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop1): ext4_map_blocks:740: inode #19: block 249: comm kworker/u4:1: lblock 41 mapped to illegal pblock 249 (length 1) EXT4-fs warning (device loop1): ext4_convert_unwritten_extents:4874: inode #19: block 41: len 1: ext4_ext_map_blocks returned -117 EXT4-fs error (device loop1): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop1) in ext4_reserve_inode_write:5866: Corrupt filesystem EXT4-fs error (device loop1): ext4_convert_unwritten_extents:4875: inode #19: comm kworker/u4:1: mark_inode_dirty error EXT4-fs (loop1): failed to convert unwritten extents to written extents -- potential data loss! (inode 19, error -117) EXT4-fs error (device loop1): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop1): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop4): ext4_map_blocks:740: inode #19: block 196: comm kworker/u4:1: lblock 4 mapped to illegal pblock 196 (length 1) EXT4-fs warning (device loop4): ext4_convert_unwritten_extents:4874: inode #19: block 4: len 1: ext4_ext_map_blocks returned -117 EXT4-fs error (device loop4): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0 EXT4-fs error (device loop4) in ext4_reserve_inode_write:5866: Corrupt filesystem EXT4-fs error (device loop4): ext4_convert_unwritten_extents:4875: inode #19: comm kworker/u4:1: mark_inode_dirty error EXT4-fs (loop4): failed to convert unwritten extents to written extents -- potential data loss! (inode 19, error -117) EXT4-fs error (device loop5): __ext4_get_inode_loc:4352: comm kworker/u4:1: Invalid inode table block 34360905424 in block_group 0