==================================================================
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 ffff888129773018 by task kworker/u4:1/10

CPU: 1 PID: 10 Comm: kworker/u4:1 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-7:0)
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>

Allocated by task 336:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466
 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+0xf7/0x260 mm/slub.c:3255
 getname_flags+0xb9/0x500 fs/namei.c:138
 getname fs/namei.c:217 [inline]
 __do_sys_rename fs/namei.c:5032 [inline]
 __se_sys_rename fs/namei.c:5029 [inline]
 __x64_sys_rename+0x6e/0x90 fs/namei.c:5029
 x64_sys_call+0x680/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
 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

Freed by task 336:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3521 [inline]
 kmem_cache_free+0x100/0x320 mm/slub.c:3539
 putname fs/namei.c:271 [inline]
 do_renameat2+0xe74/0xf60 fs/namei.c:5011
 __do_sys_rename fs/namei.c:5031 [inline]
 __se_sys_rename fs/namei.c:5029 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:5029
 x64_sys_call+0x680/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
 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

The buggy address belongs to the object at ffff888129772200
 which belongs to the cache names_cache of size 4096
The buggy address is located 3608 bytes inside of
 4096-byte region [ffff888129772200, ffff888129773200)
The buggy address belongs to the page:
page:ffffea0004a5dc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129770
head:ffffea0004a5dc00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000122 ffff8881001c5680
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 336, ts 25930661437, free_ts 25623053862
 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]
 kmem_cache_alloc+0x138/0x260 mm/slub.c:3255
 getname_flags+0xb9/0x500 fs/namei.c:138
 user_path_at_empty+0x30/0x1c0 fs/namei.c:2882
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xfb/0xa60 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat+0xc6/0x340 fs/stat.c:405
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:405
 x64_sys_call+0x2c1/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:263
 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
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_pages_ok+0x91a/0x9e0 mm/page_alloc.c:1772
 free_the_page mm/page_alloc.c:807 [inline]
 __free_pages+0xf6/0x100 mm/page_alloc.c:5871
 free_nonslab_page+0x86/0xc0 mm/slub.c:3559
 kfree+0x19a/0x270 mm/slub.c:4580
 kvfree+0x35/0x40 mm/util.c:664
 btf_add_type kernel/bpf/btf.c:1476 [inline]
 btf_check_all_metas+0x5f1/0xa70 kernel/bpf/btf.c:4017
 btf_parse_vmlinux+0x3f4/0xdf0 kernel/bpf/btf.c:4598
 bpf_get_btf_vmlinux kernel/bpf/verifier.c:13987 [inline]
 bpf_check+0x640/0xf330 kernel/bpf/verifier.c:14026
 bpf_prog_load+0x1042/0x1550 kernel/bpf/syscall.c:2328
 __sys_bpf+0x4c3/0x730 kernel/bpf/syscall.c:4633
 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4735 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:4735
 x64_sys_call+0x4b9/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 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:
 ffff888129772f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888129772f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888129773000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888129773080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888129773100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2433!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 10 Comm: kworker/u4:1 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-7:0)
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:ffffc900000a7100 EFLAGS: 00010293
RAX: ffffffff81d9272d RBX: ffff888112983018 RCX: ffff888100274f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed10225305fc
R10: ffffed10225305fc R11: 1ffff110225305fb 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: 000020000000f000 CR3: 000000011daf8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 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 6f33d6fd3bd8805d ]---
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:ffffc900000a7100 EFLAGS: 00010293
RAX: ffffffff81d9272d RBX: ffff888112983018 RCX: ffff888100274f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed10225305fc
R10: ffffed10225305fc R11: 1ffff110225305fb 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: 000055557228f4a8 CR3: 000000010d2bb000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400