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BUG: KASAN: use-after-free in poly1305_update_arch+0x259/0x7d0 arch/x86/crypto/poly1305_glue.c:198
Read of size 8 at addr ffff88806e001850 by task syz.3.57/5557

CPU: 1 PID: 5557 Comm: syz.3.57 Not tainted 6.10.0-syzkaller-00017-g5e0497553643 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 poly1305_update_arch+0x259/0x7d0 arch/x86/crypto/poly1305_glue.c:198
 crypto_poly1305_update+0x28/0x40 arch/x86/crypto/poly1305_glue.c:230
 bch2_checksum+0x5e9/0x770 fs/bcachefs/checksum.c:229
 bch2_btree_node_read_done+0x13de/0x6750 fs/bcachefs/btree_io.c:1115
 btree_node_read_work+0x68b/0x1260 fs/bcachefs/btree_io.c:1345
 bch2_btree_node_read+0x2433/0x2a10
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1769 [inline]
 bch2_btree_root_read+0x61e/0x970 fs/bcachefs/btree_io.c:1793
 read_btree_roots+0x22d/0x7c0 fs/bcachefs/recovery.c:481
 bch2_fs_recovery+0x235c/0x3730 fs/bcachefs/recovery.c:809
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1038
 bch2_fs_open+0xa8d/0xdf0 fs/bcachefs/super.c:2135
 bch2_mount+0x6b0/0x13c0 fs/bcachefs/fs.c:1932
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2a0 fs/super.c:1789
 do_new_mount+0x2be/0xb40 fs/namespace.c:3352
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 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
RIP: 0033:0x7f098e9772da
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 7e 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f098f72ee78 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f098f72ef00 RCX: 00007f098e9772da
RDX: 0000000020011a00 RSI: 0000000020011a40 RDI: 00007f098f72eec0
RBP: 0000000020011a00 R08: 00007f098f72ef00 R09: 0000000001200014
R10: 0000000001200014 R11: 0000000000000206 R12: 0000000020011a40
R13: 00007f098f72eec0 R14: 00000000000119f6 R15: 00000000200014c0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x80 pfn:0x6e001
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001832e08 ffffea0001b80008 0000000000000000
raw: 0000000000000080 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 5097, tgid 5097 (udevd), ts 81189141016, free_ts 82912556112
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
 prep_new_page mm/page_alloc.c:1481 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_pages_noprof mm/mempolicy.c:2336 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2343
 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008
 page_cache_ra_unbounded+0x1f4/0x7f0 mm/readahead.c:248
 do_page_cache_ra mm/readahead.c:303 [inline]
 force_page_cache_ra+0x2a7/0x310 mm/readahead.c:334
 page_cache_sync_readahead include/linux/pagemap.h:1313 [inline]
 filemap_get_pages+0x49d/0x2090 mm/filemap.c:2529
 filemap_read+0x457/0xfa0 mm/filemap.c:2625
 blkdev_read_iter+0x2df/0x440 block/fops.c:749
 new_sync_read fs/read_write.c:395 [inline]
 vfs_read+0x9bd/0xbc0 fs/read_write.c:476
 ksys_read+0x1a0/0x2c0 fs/read_write.c:619
 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
page last free pid 5076 tgid 5076 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_folios+0xf12/0x19c0 mm/page_alloc.c:2637
 folios_put_refs+0x93a/0xa60 mm/swap.c:1024
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x47b/0xfc0 mm/truncate.c:362
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x108/0x250 block/bdev.c:664
 blkdev_put_whole block/bdev.c:671 [inline]
 bdev_release+0x466/0x700 block/bdev.c:1096
 blkdev_release+0x15/0x20 block/fops.c:623
 __fput+0x24a/0x8a0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x360 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88806e001700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806e001780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806e001800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff88806e001880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806e001900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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