==================================================================
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 ffff888111e91018 by task kworker/u4:1/10

CPU: 0 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-7:2)
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 370:
 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_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc_track_caller+0x13c/0x2c0 mm/slub.c:4954
 kmalloc_reserve net/core/skbuff.c:357 [inline]
 __alloc_skb+0x21a/0x740 net/core/skbuff.c:428
 alloc_skb_fclone include/linux/skbuff.h:1233 [inline]
 tipc_buf_acquire net/tipc/msg.c:72 [inline]
 tipc_msg_build+0xd1/0xfb0 net/tipc/msg.c:390
 __tipc_sendmsg+0x1651/0x2680 net/tipc/socket.c:1505
 tipc_sendmsg+0x55/0x70 net/tipc/socket.c:1403
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 sock_sendmsg net/socket.c:739 [inline]
 kernel_sendmsg+0x1f8/0x2e0 net/socket.c:763
 sock_no_sendpage+0xeb/0x130 net/core/sock.c:3043
 kernel_sendpage+0x23e/0x2c0 net/socket.c:3539
 sock_sendpage+0x86/0xb0 net/socket.c:1025
 pipe_to_sendpage+0x21c/0x310 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x325/0x8e0 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0xf3/0x150 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0xe9/0x120 fs/splice.c:936
 splice_direct_to_actor+0x4cd/0xb30 fs/splice.c:891
 do_splice_direct+0x1b3/0x2c0 fs/splice.c:979
 do_sendfile+0x5c6/0xeb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1317 [inline]
 __se_sys_sendfile64 fs/read_write.c:1303 [inline]
 __x64_sys_sendfile64+0x18f/0x1f0 fs/read_write.c:1303
 x64_sys_call+0x88d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:41
 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 370:
 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]
 kfree+0xc4/0x270 mm/slub.c:4583
 skb_free_head net/core/skbuff.c:656 [inline]
 skb_release_data+0x814/0xa10 net/core/skbuff.c:678
 skb_release_all net/core/skbuff.c:743 [inline]
 __kfree_skb net/core/skbuff.c:757 [inline]
 kfree_skb_reason net/core/skbuff.c:778 [inline]
 kfree_skb+0xb9/0x2f0 net/core/skbuff.c:792
 tipc_msg_reverse+0x188/0x900 net/tipc/msg.c:672
 tipc_sk_rcv+0x1ce4/0x2c60 net/tipc/socket.c:2516
 tipc_node_xmit+0x256/0xce0 net/tipc/node.c:1703
 __tipc_sendmsg+0x1ab3/0x2680 net/tipc/socket.c:1515
 tipc_sendmsg+0x55/0x70 net/tipc/socket.c:1403
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 sock_sendmsg net/socket.c:739 [inline]
 kernel_sendmsg+0x1f8/0x2e0 net/socket.c:763
 sock_no_sendpage+0xeb/0x130 net/core/sock.c:3043
 kernel_sendpage+0x23e/0x2c0 net/socket.c:3539
 sock_sendpage+0x86/0xb0 net/socket.c:1025
 pipe_to_sendpage+0x21c/0x310 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x325/0x8e0 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0xf3/0x150 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0xe9/0x120 fs/splice.c:936
 splice_direct_to_actor+0x4cd/0xb30 fs/splice.c:891
 do_splice_direct+0x1b3/0x2c0 fs/splice.c:979
 do_sendfile+0x5c6/0xeb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1317 [inline]
 __se_sys_sendfile64 fs/read_write.c:1303 [inline]
 __x64_sys_sendfile64+0x18f/0x1f0 fs/read_write.c:1303
 x64_sys_call+0x88d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:41
 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 ffff888111e90000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4120 bytes inside of
 8192-byte region [ffff888111e90000, ffff888111e92000)
The buggy address belongs to the page:
page:ffffea000447a400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111e90
head:ffffea000447a400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043500
raw: 0000000000000000 0000000000020002 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 370, ts 25288747871, free_ts 25288351844
 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]
 __alloc_skb+0x21a/0x740 net/core/skbuff.c:428
 alloc_skb_fclone include/linux/skbuff.h:1233 [inline]
 tipc_buf_acquire net/tipc/msg.c:72 [inline]
 tipc_msg_build+0xd1/0xfb0 net/tipc/msg.c:390
 __tipc_sendmsg+0x1651/0x2680 net/tipc/socket.c:1505
 tipc_sendmsg+0x55/0x70 net/tipc/socket.c:1403
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 sock_sendmsg net/socket.c:739 [inline]
 kernel_sendmsg+0x1f8/0x2e0 net/socket.c:763
 sock_no_sendpage+0xeb/0x130 net/core/sock.c:3043
 kernel_sendpage+0x23e/0x2c0 net/socket.c:3539
 sock_sendpage+0x86/0xb0 net/socket.c:1025
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+0xf7/0x260 mm/slub.c:3255
 kmem_cache_alloc_node include/linux/slab.h:489 [inline]
 __alloc_skb+0xe0/0x740 net/core/skbuff.c:416
 alloc_skb_fclone include/linux/skbuff.h:1233 [inline]
 tipc_buf_acquire net/tipc/msg.c:72 [inline]
 tipc_msg_build+0xd1/0xfb0 net/tipc/msg.c:390

Memory state around the buggy address:
 ffff888111e90f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111e90f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888111e91000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888111e91080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111e91100: 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-7:2)
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: ffff8881119e8730 RCX: ffff888100272780
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed102233d0df
R10: ffffed102233d0df R11: 1ffff1102233d0de 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: 00005555826304a8 CR3: 000000010d380000 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 041c1372e6e89350 ]---
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: ffff8881119e8730 RCX: ffff888100272780
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed102233d0df
R10: ffffed102233d0df R11: 1ffff1102233d0de R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d719ff8 CR3: 000000010c4d7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400