================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbab/0xdb0 fs/ext4/extents.c:946 Read of size 4 at addr ffff88811edacd2c by task syz-executor.4/458 CPU: 1 PID: 458 Comm: syz-executor.4 Not tainted 5.15.122-syzkaller-06757-g1463976ddc64 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description+0x87/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x179/0x1c0 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+0xbab/0xdb0 fs/ext4/extents.c:946 ext4_ext_map_blocks+0x254/0x7250 fs/ext4/extents.c:4103 ext4_map_blocks+0xaa7/0x1e00 fs/ext4/inode.c:646 mpage_map_one_extent fs/ext4/inode.c:2409 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2462 [inline] ext4_writepages+0x1628/0x4000 fs/ext4/inode.c:2830 do_writepages+0x40e/0x670 mm/page-writeback.c:2366 filemap_fdatawrite_wbc+0x248/0x2a0 mm/filemap.c:400 __filemap_fdatawrite_range mm/filemap.c:433 [inline] file_write_and_wait_range+0x1cb/0x2b0 mm/filemap.c:810 ext4_sync_file+0x1a2/0xa50 fs/ext4/fsync.c:151 vfs_fsync_range+0x17b/0x190 fs/sync.c:188 generic_write_sync include/linux/fs.h:2980 [inline] ext4_buffered_write_iter+0x568/0x610 fs/ext4/file.c:277 ext4_file_write_iter+0x443/0x1c80 call_write_iter include/linux/fs.h:2159 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xd5d/0x1110 fs/read_write.c:594 ksys_write+0x199/0x2c0 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:656 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd0f15c1859 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:00007fd0f11440c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd0f16e0f80 RCX: 00007fd0f15c1859 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000007 RBP: 00007fd0f161dad0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd0f16e0f80 R15: 00007ffdac0990b8 The buggy address belongs to the page: page:ffffea00047b6b00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x11edac flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea00048fcc08 ffffea00048fcac8 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 464, ts 44841721841, free_ts 44891550277 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2600 prep_new_page mm/page_alloc.c:2606 [inline] get_page_from_freelist+0x2ed2/0x2f90 mm/page_alloc.c:4474 __alloc_pages+0x206/0x5e0 mm/page_alloc.c:5765 __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+0x200/0x1b00 mm/memory.c:3185 do_wp_page+0x6fa/0xb60 handle_pte_fault+0x72e/0x2340 mm/memory.c:4858 do_handle_mm_fault+0x1fed/0x2330 mm/memory.c:5240 do_user_addr_fault arch/x86/mm/fault.c:1365 [inline] handle_page_fault arch/x86/mm/fault.c:1549 [inline] exc_page_fault+0x26f/0x830 arch/x86/mm/fault.c:1605 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:568 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1467 [inline] free_pcp_prepare mm/page_alloc.c:1539 [inline] free_unref_page_prepare+0x7c8/0x7d0 mm/page_alloc.c:3523 free_unref_page_list+0x14b/0xa60 mm/page_alloc.c:3660 release_pages+0x1310/0x1370 mm/swap.c:1009 free_pages_and_swap_cache+0x8a/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+0x177/0x320 mm/mmu_gather.c:338 exit_mmap+0x3ef/0x6f0 mm/mmap.c:3211 __mmput+0x95/0x310 kernel/fork.c:1171 mmput+0x5b/0x170 kernel/fork.c:1194 exit_mm kernel/exit.c:551 [inline] do_exit+0xbb4/0x2b60 kernel/exit.c:862 do_group_exit+0x141/0x310 kernel/exit.c:997 get_signal+0x7a3/0x1630 kernel/signal.c:2891 arch_do_signal_or_restart+0xbd/0x1680 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0xa0/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x26/0x160 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff88811edacc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88811edacc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88811edacd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88811edacd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88811edace00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop4): ext4_map_blocks:716: inode #19: block 36: comm syz-executor.4: lblock 36 mapped to illegal pblock 36 (length 12) EXT4-fs (loop4): Delayed block allocation failed for inode 19 at logical offset 36 with max blocks 12 with error 117 EXT4-fs (loop4): This should not happen!! Data will be lost