================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x66c/0xa14 fs/reiserfs/lbalance.c:-1 Read of size 48 at addr ffff0000f7bacff0 by task syz.5.188/5622 CPU: 1 PID: 5622 Comm: syz.5.188 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 leaf_paste_in_buffer+0x66c/0xa14 fs/reiserfs/lbalance.c:-1 leaf_copy_dir_entries+0x45c/0x788 fs/reiserfs/lbalance.c:108 leaf_copy_boundary_item+0x888/0x19dc fs/reiserfs/lbalance.c:-1 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline] leaf_move_items+0x6a0/0xbb0 fs/reiserfs/lbalance.c:726 leaf_shift_left+0xc8/0x3ac fs/reiserfs/lbalance.c:750 balance_leaf_when_delete_left fs/reiserfs/do_balan.c:194 [inline] balance_leaf_when_delete fs/reiserfs/do_balan.c:272 [inline] balance_leaf+0x27b0/0xd92c fs/reiserfs/do_balan.c:1393 do_balance+0x270/0x790 fs/reiserfs/do_balan.c:1888 reiserfs_delete_item+0x8fc/0xc94 fs/reiserfs/stree.c:1371 direct2indirect+0x7d4/0xec4 fs/reiserfs/tail_conversion.c:139 reiserfs_get_block+0x31fc/0x36e8 fs/reiserfs/inode.c:949 __block_write_begin_int+0x350/0x1388 fs/buffer.c:1991 __block_write_begin+0x7c/0xa0 fs/buffer.c:2041 reiserfs_write_begin+0x328/0x714 fs/reiserfs/inode.c:2775 generic_perform_write+0x234/0x4f4 mm/filemap.c:3862 __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3ec/0x7f0 fs/read_write.c:584 ksys_write+0x12c/0x224 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the physical page: page:000000009dcc1521 refcount:3 mapcount:0 mapping:00000000a61eb10b index:0x22e pfn:0x137bac memcg:ffff0000daa86000 aops:def_blk_aops ino:700005 flags: 0x5ffc40000002042(referenced|workingset|private|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc40000002042 0000000000000000 dead000000000122 ffff0000c0498818 raw: 000000000000022e ffff0000fc1fd0e8 00000003ffffffff ffff0000daa86000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f7bacf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f7bacf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f7bad000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff0000f7bad080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff0000f7bad100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== REISERFS error (device loop5): vs-4010 is_reusable: block number is out of range 11822 (1024) REISERFS (device loop5): Remounting filesystem read-only REISERFS error (device loop5): vs-4010 is_reusable: block number is out of range 262180 (1024) REISERFS error (device loop5): vs-4010 is_reusable: block number is out of range 589868 (1024) REISERFS error (device loop5): vs-4080 _reiserfs_free_block: block 1: bit already cleared ------------[ cut here ]------------ WARNING: CPU: 1 PID: 5622 at fs/reiserfs/journal.c:3397 journal_end+0x1b0/0x270 fs/reiserfs/journal.c:3397 Modules linked in: CPU: 1 PID: 5622 Comm: syz.5.188 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : journal_end+0x1b0/0x270 fs/reiserfs/journal.c:3397 lr : journal_end+0x1b0/0x270 fs/reiserfs/journal.c:3397 sp : ffff8000209e7620 x29: ffff8000209e7620 x28: 1fffe0001f84f1df x27: 1ffff0000413cede x26: 1ffff0000413cedc x25: 1fffe0001a0635c0 x24: dfff800000000000 x23: 00000000fffffffb x22: 0000000000000000 x21: ffff8000209e76f4 x20: ffff0000d031ae00 x19: ffff8000209e76e0 x18: ffff800011babf60 x17: 1fffe00033ea397e x16: ffff800011a529a8 x15: 0000000000000002 x14: 0000000000000006 x13: 1ffff0000413cedd x12: 0000000000080000 x11: 000000000004dd66 x10: ffff800033740000 x9 : ffff800008cea280 x8 : 000000000004dd67 x7 : 0000000000000000 x6 : ffff800008d02a78 x5 : 0000000000000000 x4 : 0000000000000008 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: journal_end+0x1b0/0x270 fs/reiserfs/journal.c:3397 reiserfs_truncate_file+0x5dc/0xb00 fs/reiserfs/inode.c:2311 reiserfs_truncate_failed_write fs/reiserfs/inode.c:2743 [inline] reiserfs_write_end+0x680/0x828 fs/reiserfs/inode.c:2958 generic_perform_write+0x300/0x4f4 mm/filemap.c:3873 __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3ec/0x7f0 fs/read_write.c:584 ksys_write+0x12c/0x224 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 irq event stamp: 398071 hardirqs last enabled at (398071): [] raw_spin_rq_unlock_irq kernel/sched/sched.h:1374 [inline] hardirqs last enabled at (398071): [] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5004 hardirqs last disabled at (398070): [] __schedule+0x298/0x1b0c kernel/sched/core.c:6460 softirqs last enabled at (397712): [] softirq_handle_end kernel/softirq.c:439 [inline] softirqs last enabled at (397712): [] handle_softirqs+0xaec/0xc60 kernel/softirq.c:624 softirqs last disabled at (397565): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]---