================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:837 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:953 Read of size 4 at addr ffff88812bb34764 by task kworker/u4:5/423 CPU: 0 PID: 423 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_ext_binsearch fs/ext4/extents.c:837 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:953 ext4_ext_map_blocks+0x207/0x61d0 fs/ext4/extents.c:4166 ext4_map_blocks+0x9d8/0x1b70 fs/ext4/inode.c:679 mpage_map_one_extent fs/ext4/inode.c:2435 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2488 [inline] ext4_writepages+0x1409/0x30e0 fs/ext4/inode.c:2856 do_writepages+0x3a4/0x5f0 mm/page-writeback.c:2494 __writeback_single_inode+0xc6/0xad0 fs/fs-writeback.c:1622 writeback_sb_inodes+0xa10/0x15d0 fs/fs-writeback.c:1913 wb_writeback+0x40b/0x9d0 fs/fs-writeback.c:2089 wb_do_writeback fs/fs-writeback.c:2236 [inline] wb_workfn+0x378/0xeb0 fs/fs-writeback.c:2276 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302 worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the physical page: page:ffffea0004aecd00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12bb34 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004a59788 ffffea0004aec9c8 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 0x141cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_WRITE), pid 422, tgid 422 (syz.3.20), ts 26868979949, free_ts 27282113412 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670 prep_new_page+0x1c/0x110 mm/page_alloc.c:2677 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5897 __folio_alloc+0x12/0x40 mm/page_alloc.c:5929 __folio_alloc_node include/linux/gfp.h:245 [inline] folio_alloc include/linux/gfp.h:274 [inline] filemap_alloc_folio include/linux/pagemap.h:515 [inline] __filemap_get_folio+0x721/0x9b0 mm/filemap.c:2018 pagecache_get_page+0x2b/0x110 mm/folio-compat.c:110 grab_cache_page_write_begin+0x43/0x60 mm/folio-compat.c:122 ext4_write_begin+0x256/0xf90 fs/ext4/inode.c:1221 ext4_da_write_begin+0x3e7/0x8c0 fs/ext4/inode.c:3001 generic_perform_write+0x32d/0x740 mm/filemap.c:3903 ext4_buffered_write_iter+0x367/0x630 fs/ext4/file.c:285 ext4_file_write_iter+0x191/0x1500 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x603/0xce0 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:706 x64_sys_call+0x36/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1578 [inline] free_pcp_prepare mm/page_alloc.c:1652 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3618 free_unref_page_list+0x117/0x8c0 mm/page_alloc.c:3769 release_pages+0xaf2/0xb50 mm/swap.c:1048 __pagevec_release+0x71/0xe0 mm/swap.c:1068 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] truncate_inode_pages_range+0x365/0xd70 mm/truncate.c:402 truncate_inode_pages mm/truncate.c:484 [inline] truncate_inode_pages_final+0x82/0x90 mm/truncate.c:523 ext4_evict_inode+0x655/0x1470 fs/ext4/inode.c:210 evict+0x4d7/0x8f0 fs/inode.c:708 dispose_list fs/inode.c:741 [inline] evict_inodes+0x5dc/0x650 fs/inode.c:795 generic_shutdown_super+0x96/0x370 fs/super.c:482 kill_block_super+0x7f/0xf0 fs/super.c:1472 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x474/0x500 fs/namespace.c:1191 __cleanup_mnt+0x19/0x20 fs/namespace.c:1198 task_work_run+0x1e1/0x250 kernel/task_work.c:203 Memory state around the buggy address: ffff88812bb34600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812bb34680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88812bb34700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88812bb34780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812bb34800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop0): ext4_map_blocks:745: inode #15: block 36: comm kworker/u4:5: lblock 36 mapped to illegal pblock 36 (length 1) EXT4-fs (loop0): Delayed block allocation failed for inode 15 at logical offset 36 with max blocks 1 with error 117 EXT4-fs (loop0): This should not happen!! Data will be lost EXT4-fs error (device loop2): ext4_map_blocks:745: inode #15: block 104979443838829: comm kworker/u4:5: lblock 0 mapped to illegal pblock 104979443838829 (length 1) EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs error (device loop2): __ext4_get_inode_loc:4515: comm kworker/u4:5: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4515: comm kworker/u4:5: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): ext4_map_blocks:745: inode #15: block 104979443838865: comm kworker/u4:5: lblock 36 mapped to illegal pblock 104979443838865 (length 1) EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 36 with max blocks 1 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop1): __ext4_get_inode_loc:4515: comm kworker/u4:5: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop1) in ext4_reserve_inode_write:5935: Corrupt filesystem EXT4-fs error (device loop1): ext4_dirty_inode:6139: inode #15: comm kworker/u4:5: mark_inode_dirty error EXT4-fs error (device loop1): ext4_read_block_bitmap_nowait:477: comm kworker/u4:5: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs (loop1): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (loop1): This should not happen!! Data will be lost EXT4-fs (loop1): Delayed block allocation failed for inode 15 at logical offset 36 with max blocks 1 with error 117 EXT4-fs (loop1): This should not happen!! Data will be lost