==================================================================
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 ffff88812e8b5018 by task kworker/u4:2/45

CPU: 1 PID: 45 Comm: kworker/u4:2 Not tainted 5.15.189-syzkaller-00079-ga71626bd56a5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:5)
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 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+0x1de/0x6280 fs/ext4/extents.c:4166
 ext4_map_blocks+0x97b/0x1b20 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+0x11e7/0x2f90 fs/ext4/inode.c:2842
 do_writepages+0x48a/0x6c0 mm/page-writeback.c:2388
 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1647
 writeback_sb_inodes+0x9c0/0x1590 fs/fs-writeback.c:1930
 wb_writeback+0x3f1/0x980 fs/fs-writeback.c:2106
 wb_do_writeback fs/fs-writeback.c:2253 [inline]
 wb_workfn+0x38f/0xe20 fs/fs-writeback.c:2294
 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
 </TASK>

The buggy address belongs to the page:
page:ffffea0004ba2d40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12e8b5
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 0000000000000000 ffffffff04ba0201 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 635, ts 29903862384, free_ts 35974120666
 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+0x2cc5/0x2d50 mm/page_alloc.c:4485
 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5795
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1932 [inline]
 new_slab+0xa1/0x4d0 mm/slub.c:1995
 ___slab_alloc+0x381/0x810 mm/slub.c:3028
 __slab_alloc+0x49/0x90 mm/slub.c:3115
 slab_alloc_node mm/slub.c:3206 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4949
 kmalloc_reserve net/core/skbuff.c:357 [inline]
 pskb_expand_head+0x11b/0x11d0 net/core/skbuff.c:1733
 skb_ensure_writable+0x2e7/0x460 net/core/skbuff.c:5811
 __bpf_try_make_writable net/core/filter.c:1667 [inline]
 bpf_try_make_writable net/core/filter.c:1673 [inline]
 bpf_try_make_head_writable net/core/filter.c:1681 [inline]
 ____bpf_clone_redirect net/core/filter.c:2447 [inline]
 bpf_clone_redirect+0x10b/0x380 net/core/filter.c:2423
 bpf_prog_1aaa155e944a1304+0xa41/0xaa0
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x33d/0x8d0 net/bpf/test_run.c:119
 bpf_prog_test_run_skb+0x9ec/0x1150 net/bpf/test_run.c:669
 bpf_prog_test_run+0x3d5/0x620 kernel/bpf/syscall.c:3348
 __sys_bpf+0x52c/0x730 kernel/bpf/syscall.c:4651
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+0xa2/0x550 mm/page_alloc.c:3616
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5871
 __free_slab+0xe8/0x1e0 mm/slub.c:2020
 free_slab mm/slub.c:2035 [inline]
 discard_slab mm/slub.c:2041 [inline]
 __unfreeze_partials+0x160/0x190 mm/slub.c:2527
 put_cpu_partial+0xc6/0x120 mm/slub.c:2607
 __slab_free+0x1d4/0x290 mm/slub.c:3390
 do_slab_free mm/slub.c:3509 [inline]
 ___cache_free+0x104/0x120 mm/slub.c:3530
 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:443
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3240 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc_trace+0xfb/0x270 mm/slub.c:3267
 kmem_cache_alloc_node_trace include/linux/slab.h:505 [inline]
 kmalloc_node include/linux/slab.h:634 [inline]
 kzalloc_node include/linux/slab.h:758 [inline]
 __get_vm_area_node+0x11d/0x350 mm/vmalloc.c:2432
 __vmalloc_node_range+0xe8/0x840 mm/vmalloc.c:3052

Memory state around the buggy address:
 ffff88812e8b4f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812e8b4f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812e8b5000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff88812e8b5080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812e8b5100: 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:2433!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 45 Comm: kworker/u4:2 Tainted: G    B             5.15.189-syzkaller-00079-ga71626bd56a5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn
 (flush-7:5)
RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2433 [inline]
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline]
RIP: 0010:ext4_writepages+0x2eed/0x2f90 fs/ext4/inode.c:2842
Code: 00 74 08 48 89 df e8 22 01 ce ff 48 8b 3b 48 8b 74 24 28 48 8b 54 24 30 44 89 e9 45 89 f0 e8 6a 9b 07 00 eb 51 e8 a3 88 8f ff <0f> 0b e8 9c 88 8f ff eb 2f e8 95 88 8f ff eb 5f e8 8e 88 8f ff 31
RSP: 0018:ffffc900002ef100 EFLAGS: 00010293

RAX: ffffffff81d9272d RBX: ffff8881119fbbc8 RCX: ffff888108782780
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900002ef470 R08: dffffc0000000000 R09: ffffed102233f772
R10: ffffed102233f772 R11: 1ffff1102233f771 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f727080cd58 CR3: 0000000121441000 CR4: 00000000003506a0
DR0: 000000000000b2d1 DR1: 0010000000000000 DR2: 0001000000000004
DR3: 0000000000000002 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_writepages+0x48a/0x6c0 mm/page-writeback.c:2388
 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1647
 writeback_sb_inodes+0x9c0/0x1590 fs/fs-writeback.c:1930
 wb_writeback+0x3f1/0x980 fs/fs-writeback.c:2106
 wb_do_writeback fs/fs-writeback.c:2253 [inline]
 wb_workfn+0x38f/0xe20 fs/fs-writeback.c:2294
 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
 </TASK>
Modules linked in:
---[ end trace bb39660072f854ab ]---
RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2433 [inline]
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline]
RIP: 0010:ext4_writepages+0x2eed/0x2f90 fs/ext4/inode.c:2842
Code: 00 74 08 48 89 df e8 22 01 ce ff 48 8b 3b 48 8b 74 24 28 48 8b 54 24 30 44 89 e9 45 89 f0 e8 6a 9b 07 00 eb 51 e8 a3 88 8f ff <0f> 0b e8 9c 88 8f ff eb 2f e8 95 88 8f ff eb 5f e8 8e 88 8f ff 31
RSP: 0018:ffffc900002ef100 EFLAGS: 00010293
RAX: ffffffff81d9272d RBX: ffff8881119fbbc8 RCX: ffff888108782780
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900002ef470 R08: dffffc0000000000 R09: ffffed102233f772
R10: ffffed102233f772 R11: 1ffff1102233f771 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa54f478178 CR3: 000000011e0ba000 CR4: 00000000003506a0
DR0: 000000000000b2d1 DR1: 0010000000000000 DR2: 0001000000000004
DR3: 0000000000000002 DR6: 00000000fffe0ff0 DR7: 0000000000000400