================================================================== 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 ffff8881279d0ec4 by task kworker/u4:1/10 CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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+0x207/0x61e0 fs/ext4/extents.c:4172 ext4_map_blocks+0x988/0x1b30 fs/ext4/inode.c:674 mpage_map_one_extent fs/ext4/inode.c:2421 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] ext4_writepages+0x123f/0x3090 fs/ext4/inode.c:2842 do_writepages+0x473/0x6c0 mm/page-writeback.c:2388 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xa10/0x1610 fs/fs-writeback.c:1940 wb_writeback+0x40b/0x9d0 fs/fs-writeback.c:2116 wb_do_writeback fs/fs-writeback.c:2263 [inline] wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2304 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:ffffea00049e7400 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x100 pfn:0x1279d0 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffffff86e534f0 ffffffff86e534f0 0000000000000000 raw: 0000000000000100 0000000000000004 00000000ffffff7f 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 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 287, ts 23848372980, free_ts 24927420763 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+0x2d3a/0x2dc0 mm/page_alloc.c:4485 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5822 __alloc_pages_node include/linux/gfp.h:595 [inline] alloc_pages_node include/linux/gfp.h:609 [inline] alloc_pages include/linux/gfp.h:622 [inline] do_anonymous_page mm/memory.c:4069 [inline] handle_pte_fault+0xebf/0x2710 mm/memory.c:4909 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1af9/0x1de0 mm/memory.c:5333 handle_mm_fault include/linux/mm.h:1847 [inline] do_user_addr_fault+0x828/0x1250 arch/x86/mm/fault.c:1416 handle_page_fault arch/x86/mm/fault.c:1507 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1560 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+0x13a/0x9d0 mm/page_alloc.c:3671 release_pages+0x1006/0x1060 mm/swap.c:1015 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+0x17e/0x310 mm/mmu_gather.c:338 unmap_region+0x344/0x3b0 mm/mmap.c:2692 __do_munmap+0xa24/0x1020 mm/mmap.c:2925 __vm_munmap+0x163/0x2b0 mm/mmap.c:2978 __do_sys_munmap mm/mmap.c:3004 [inline] __se_sys_munmap mm/mmap.c:3000 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3000 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: ffff8881279d0d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881279d0e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881279d0e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881279d0f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881279d0f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop2): ext4_map_blocks:740: inode #15: block 60898881321060: comm kworker/u4:1: lblock 1 mapped to illegal pblock 60898881321060 (length 3) EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): ext4_map_blocks:740: inode #15: block 60898881321075: comm kworker/u4:1: lblock 16 mapped to illegal pblock 60898881321075 (length 1) EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: 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_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop3): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop3) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs error (device loop3): ext4_dirty_inode:6089: inode #15: comm kworker/u4:1: mark_inode_dirty error EXT4-fs error (device loop3): ext4_read_block_bitmap_nowait:476: comm kworker/u4:1: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop3): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop3) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop3): This should not happen!! Data will be lost EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop3): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: 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_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop4): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop4) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs error (device loop4): ext4_dirty_inode:6089: inode #15: comm kworker/u4:1: mark_inode_dirty error EXT4-fs error (device loop4): ext4_read_block_bitmap_nowait:476: comm kworker/u4:1: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop4): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop4) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop4): This should not happen!! Data will be lost EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop4): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: 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_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop6): ext4_map_blocks:740: inode #15: block 128043518817397: comm kworker/u4:1: lblock 1 mapped to illegal pblock 128043518817397 (length 3) EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop6): This should not happen!! Data will be lost EXT4-fs error (device loop6): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop6): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop6): ext4_map_blocks:740: inode #15: block 128043518817412: comm kworker/u4:1: lblock 16 mapped to illegal pblock 128043518817412 (length 1) EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop6): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: 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_macvtap: 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 (loop8): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 28 EXT4-fs (loop8): This should not happen!! Data will be lost EXT4-fs (loop8): Total free blocks count 0 EXT4-fs (loop8): Free/Dirty block details EXT4-fs (loop8): free_blocks=16 EXT4-fs (loop8): dirty_blocks=0 EXT4-fs (loop8): Block reservation details EXT4-fs (loop8): i_reserved_data_blocks=0 IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): 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_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_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 EXT4-fs error (device loop9): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop9) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs error (device loop9): ext4_dirty_inode:6089: inode #15: comm kworker/u4:1: mark_inode_dirty error EXT4-fs error (device loop9): ext4_read_block_bitmap_nowait:476: comm kworker/u4:1: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop9): __ext4_get_inode_loc:4358: comm kworker/u4:1: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop9) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs (loop9): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop9): This should not happen!! Data will be lost EXT4-fs (loop9): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop9): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state 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): 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_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_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