==================================================================
BUG: KASAN: slab-use-after-free in __bch2_write+0x5dbd/0x5dd0 fs/bcachefs/io_write.c:1410
Read of size 2 at addr ffff8880328d183c by task kworker/u8:1/12

CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.13.0-rc1-syzkaller-00316-gb5f217084ab3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-bcachefs-3)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 __bch2_write+0x5dbd/0x5dd0 fs/bcachefs/io_write.c:1410
 bch2_write+0x9b5/0x1760 fs/bcachefs/io_write.c:1631
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:449 [inline]
 bch2_writepages+0x284/0x390 fs/bcachefs/fs-io-buffered.c:641
 do_writepages+0x361/0x880 mm/page-writeback.c:2702
 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 12:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4104 [inline]
 slab_alloc_node mm/slub.c:4153 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160
 mempool_alloc_noprof+0x199/0x5a0 mm/mempool.c:402
 bio_alloc_bioset+0x26f/0x1130 block/bio.c:554
 bch2_writepage_io_alloc fs/bcachefs/fs-io-buffered.c:465 [inline]
 __bch2_writepage+0x1443/0x2b10 fs/bcachefs/fs-io-buffered.c:599
 write_cache_pages+0xd2/0x230 mm/page-writeback.c:2659
 bch2_writepages+0x156/0x390 fs/bcachefs/fs-io-buffered.c:639
 do_writepages+0x361/0x880 mm/page-writeback.c:2702
 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 6094:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2338 [inline]
 slab_free_after_rcu_debug+0x11a/0x280 mm/slub.c:4648
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaac/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:655
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 slab_free_hook mm/slub.c:2299 [inline]
 slab_free mm/slub.c:4598 [inline]
 kmem_cache_free+0x2fb/0x410 mm/slub.c:4700
 bch2_writepage_io_done+0x5c1/0x670 fs/bcachefs/fs-io-buffered.c:441
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Second to last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390
 queue_work include/linux/workqueue.h:662 [inline]
 closure_queue include/linux/closure.h:268 [inline]
 closure_put_after_sub+0x2b1/0x330 lib/closure.c:42
 bch2_nocow_write+0x522e/0x5720 fs/bcachefs/io_write.c:1367
 __bch2_write+0x5b9b/0x5dd0 fs/bcachefs/io_write.c:1409
 bch2_write+0x9b5/0x1760 fs/bcachefs/io_write.c:1631
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:449 [inline]
 bch2_writepages+0x284/0x390 fs/bcachefs/fs-io-buffered.c:641
 do_writepages+0x361/0x880 mm/page-writeback.c:2702
 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff8880328d17c0
 which belongs to the cache bio-106 of size 1064
The buggy address is located 124 bytes inside of
 freed 1064-byte region [ffff8880328d17c0, ffff8880328d1be8)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x328d0
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888033e90dc0 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800d000d 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888033e90dc0 dead000000000122 0000000000000000
head: 0000000000000000 00000000800d000d 00000001f5000000 0000000000000000
head: 00fff00000000002 ffffea0000ca3401 ffffffffffffffff 0000000000000000
head: ffff888000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6059, tgid 6058 (syz.5.32), ts 94496766803, free_ts 94491313241
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x140 mm/slub.c:2408
 allocate_slab+0x5a/0x2f0 mm/slub.c:2574
 new_slab mm/slub.c:2627 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815
 __slab_alloc+0x58/0xa0 mm/slub.c:3905
 __slab_alloc_node mm/slub.c:3980 [inline]
 slab_alloc_node mm/slub.c:4141 [inline]
 kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4160
 mempool_init_node+0x1f0/0x4e0 mm/mempool.c:217
 mempool_init_noprof+0x3a/0x50 mm/mempool.c:246
 bioset_init+0x2e8/0x820 block/bio.c:1800
 bch2_fs_fs_io_buffered_init+0x2b/0x50 fs/bcachefs/fs-io-buffered.c:1073
 bch2_fs_alloc fs/bcachefs/super.c:931 [inline]
 bch2_fs_open+0x2d4f/0x2f80 fs/bcachefs/super.c:2065
 bch2_fs_get_tree+0x738/0x1710 fs/bcachefs/fs.c:2157
 vfs_get_tree+0x92/0x2b0 fs/super.c:1814
page last free pid 6077 tgid 6075 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xdef/0x1130 mm/page_alloc.c:2657
 stack_depot_save_flags+0x6f6/0x830 lib/stackdepot.c:666
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x51/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4104 [inline]
 slab_alloc_node mm/slub.c:4153 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160
 dst_alloc+0x12b/0x190 net/core/dst.c:89
 rt_dst_alloc net/ipv4/route.c:1625 [inline]
 __mkroute_output net/ipv4/route.c:2617 [inline]
 ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2839
 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2668
 __ip_route_output_key include/net/route.h:141 [inline]
 ip_route_connect include/net/route.h:331 [inline]
 tcp_v4_connect+0x6df/0x1ba0 net/ipv4/tcp_ipv4.c:250
 __inet_stream_connect+0x264/0xf30 net/ipv4/af_inet.c:677
 inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:748
 __sys_connect_file net/socket.c:2055 [inline]
 __sys_connect+0x28a/0x2d0 net/socket.c:2074
 __do_sys_connect net/socket.c:2080 [inline]
 __se_sys_connect net/socket.c:2077 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2077
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880328d1700: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
 ffff8880328d1780: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff8880328d1800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8880328d1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880328d1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================