==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xbea/0xe30 fs/ext4/extents.c:946
Read of size 4 at addr ffff88812215a078 by task kworker/u4:3/198

CPU: 1 PID: 198 Comm: kworker/u4:3 Not tainted 5.15.173-syzkaller-1077948-gb4bd207b0380 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1c0 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+0xbea/0xe30 fs/ext4/extents.c:946
 ext4_ext_map_blocks+0x269/0x7450 fs/ext4/extents.c:4165
 ext4_map_blocks+0xa60/0x1c70 fs/ext4/inode.c:673
 mpage_map_one_extent fs/ext4/inode.c:2420 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2473 [inline]
 ext4_writepages+0x1628/0x4000 fs/ext4/inode.c:2841
 do_writepages+0x40e/0x670 mm/page-writeback.c:2388
 __writeback_single_inode+0xdf/0xa70 fs/fs-writeback.c:1647
 writeback_sb_inodes+0xb2a/0x1920 fs/fs-writeback.c:1930
 wb_writeback+0x3b9/0x9e0 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x3d9/0x1110 fs/fs-writeback.c:2288
 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325
 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472
 kthread+0x421/0x510 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

The buggy address belongs to the page:
page:ffffea0004885680 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12215a
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea000486bf48 ffffea0004885648 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 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 324, ts 38822156189, free_ts 38837032421
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4485
 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5779
 __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]
 do_anonymous_page mm/memory.c:4066 [inline]
 handle_pte_fault+0xe7e/0x25c0 mm/memory.c:4903
 do_handle_mm_fault+0x20bc/0x2400 mm/memory.c:5327
 handle_mm_fault include/linux/mm.h:1836 [inline]
 do_user_addr_fault arch/x86/mm/fault.c:1418 [inline]
 handle_page_fault arch/x86/mm/fault.c:1509 [inline]
 exc_page_fault+0x3b5/0x7f0 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+0x7c8/0x7d0 mm/page_alloc.c:3534
 free_unref_page_list+0x14b/0xa60 mm/page_alloc.c:3671
 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
 unmap_region+0x304/0x350 mm/mmap.c:2691
 __do_munmap+0x1421/0x1a90 mm/mmap.c:2925
 __vm_munmap+0x166/0x2a0 mm/mmap.c:2948
 __do_sys_munmap mm/mmap.c:2974 [inline]
 __se_sys_munmap mm/mmap.c:2970 [inline]
 __x64_sys_munmap+0x6b/0x80 mm/mmap.c:2970
 x64_sys_call+0x75/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888122159f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888122159f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812215a000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88812215a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812215a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2432!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 198 Comm: kworker/u4:3 Tainted: G    B             5.15.173-syzkaller-1077948-gb4bd207b0380 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2432 [inline]
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2473 [inline]
RIP: 0010:ext4_writepages+0x3f4b/0x4000 fs/ext4/inode.c:2841
Code: 00 74 08 48 89 df e8 84 b5 c9 ff 48 8b 3b 48 8b 74 24 48 48 8b 54 24 28 44 89 e9 45 89 f8 e8 fc 3f 08 00 eb 58 e8 35 5d 87 ff <0f> 0b e8 2e 5d 87 ff eb 3b e8 27 5d 87 ff eb 72 e8 20 5d 87 ff 31
RSP: 0018:ffffc90000aa7000 EFLAGS: 00010293
RAX: ffffffff81e9097b RBX: dffffc0000000000 RCX: ffff88811b420000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000aa7410 R08: ffffffff81e8e33b R09: ffffed10222b78e8
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffffc90000aa72e0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c001198000 CR3: 000000010ce54000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_writepages+0x40e/0x670 mm/page-writeback.c:2388
 __writeback_single_inode+0xdf/0xa70 fs/fs-writeback.c:1647
 writeback_sb_inodes+0xb2a/0x1920 fs/fs-writeback.c:1930
 wb_writeback+0x3b9/0x9e0 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x3d9/0x1110 fs/fs-writeback.c:2288
 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325
 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472
 kthread+0x421/0x510 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace 2c7381bb5575c5cb ]---
RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2432 [inline]
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2473 [inline]
RIP: 0010:ext4_writepages+0x3f4b/0x4000 fs/ext4/inode.c:2841
Code: 00 74 08 48 89 df e8 84 b5 c9 ff 48 8b 3b 48 8b 74 24 48 48 8b 54 24 28 44 89 e9 45 89 f8 e8 fc 3f 08 00 eb 58 e8 35 5d 87 ff <0f> 0b e8 2e 5d 87 ff eb 3b e8 27 5d 87 ff eb 72 e8 20 5d 87 ff 31
RSP: 0018:ffffc90000aa7000 EFLAGS: 00010293
RAX: ffffffff81e9097b RBX: dffffc0000000000 RCX: ffff88811b420000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000aa7410 R08: ffffffff81e8e33b R09: ffffed10222b78e8
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffffc90000aa72e0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555557ec2818 CR3: 000000010d119000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400