IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
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 ffff88811bc3030c by task kworker/u4:3/352

CPU: 1 PID: 352 Comm: kworker/u4:3 Not tainted 6.1.145-syzkaller-00038-g3b4ff5af8d36 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x71/0x210 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:427
 kasan_report+0x122/0x150 mm/kasan/report.c:531
 __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+0x1dc/0x6060 fs/ext4/extents.c:4166
 ext4_map_blocks+0x9cb/0x1b60 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+0x1260/0x3020 fs/ext4/inode.c:2856
 do_writepages+0x3a9/0x5e0 mm/page-writeback.c:2494
 __writeback_single_inode+0xc6/0xad0 fs/fs-writeback.c:1612
 writeback_sb_inodes+0x9b8/0x1550 fs/fs-writeback.c:1903
 wb_writeback+0x3f1/0x980 fs/fs-writeback.c:2079
 wb_do_writeback fs/fs-writeback.c:2226 [inline]
 wb_workfn+0x350/0xda0 fs/fs-writeback.c:2266
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:397
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00046f0c00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x11bc30
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea00046f0c48 ffffea00046f0bc8 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 0x8140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO|__GFP_CMA), pid 278, tgid 278 (sshd-session), ts 23266233785, free_ts 23285287138
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2637
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2644
 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4544
 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5858
 __folio_alloc+0x12/0x40 mm/page_alloc.c:5890
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 alloc_page_vma include/linux/gfp.h:283 [inline]
 do_anonymous_page mm/memory.c:4283 [inline]
 handle_pte_fault mm/memory.c:5169 [inline]
 __handle_mm_fault mm/memory.c:5313 [inline]
 handle_mm_fault+0x18ef/0x2640 mm/memory.c:5453
 do_user_addr_fault+0x905/0x1050 arch/x86/mm/fault.c:1323
 handle_page_fault arch/x86/mm/fault.c:1466 [inline]
 exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1522
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1545 [inline]
 free_pcp_prepare mm/page_alloc.c:1619 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3581
 free_unref_page_list+0x112/0x8b0 mm/page_alloc.c:3730
 release_pages+0xad1/0xb20 mm/swap.c:1043
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:315
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu mm/mmu_gather.c:261 [inline]
 tlb_finish_mmu+0x1aa/0x370 mm/mmu_gather.c:361
 unmap_region+0x28d/0x2e0 mm/mmap.c:2414
 do_mas_align_munmap+0xb9b/0x1230 mm/mmap.c:2688
 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2746
 __vm_munmap+0x19f/0x2f0 mm/mmap.c:3045
 __do_sys_munmap mm/mmap.c:3071 [inline]
 __se_sys_munmap mm/mmap.c:3067 [inline]
 __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3067
 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88811bc30200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811bc30280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88811bc30300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff88811bc30380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811bc30400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop3): ext4_map_blocks:745: inode #15: block 194914205859797: comm kworker/u4:3: lblock 0 mapped to illegal pblock 194914205859797 (length 1)
EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (loop3): This should not happen!! Data will be lost