================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x1b8/0xab0 fs/reiserfs/lbalance.c:1017 Write of size 3936 at addr ffff8880595f5140 by task syz.1.1315/11712 CPU: 0 PID: 11712 Comm: syz.1.1315 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189 memmove+0x3c/0x60 mm/kasan/shadow.c:55 leaf_paste_in_buffer+0x1b8/0xab0 fs/reiserfs/lbalance.c:1017 leaf_copy_boundary_item+0xcbf/0x21b0 fs/reiserfs/lbalance.c:199 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline] leaf_move_items+0xcd0/0x28a0 fs/reiserfs/lbalance.c:726 leaf_shift_left+0xba/0x430 fs/reiserfs/lbalance.c:750 balance_leaf_paste_left_shift fs/reiserfs/do_balan.c:458 [inline] balance_leaf_paste_left fs/reiserfs/do_balan.c:592 [inline] balance_leaf_left fs/reiserfs/do_balan.c:613 [inline] balance_leaf+0x3071/0x12510 fs/reiserfs/do_balan.c:1409 do_balance+0x309/0x8f0 fs/reiserfs/do_balan.c:1888 reiserfs_paste_into_item+0x73b/0x880 fs/reiserfs/stree.c:2159 reiserfs_get_block+0x226a/0x5390 fs/reiserfs/inode.c:1077 __block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012 reiserfs_write_begin+0x346/0x810 fs/reiserfs/inode.c:2790 generic_cont_expand_simple+0x144/0x230 fs/buffer.c:2362 reiserfs_setattr+0x3ff/0xf90 fs/reiserfs/inode.c:3319 notify_change+0xc6d/0xf50 fs/attr.c:505 do_truncate+0x21c/0x300 fs/open.c:65 vfs_truncate+0x2dd/0x3a0 fs/open.c:111 do_sys_truncate+0xda/0x190 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa5aa09f169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fa5a7ee7038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007fa5aa2b8080 RCX: 00007fa5aa09f169 RDX: 0000000000000000 RSI: 0000000008800000 RDI: 0000400000000080 RBP: 00007fa5aa1202a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fa5aa2b8080 R15: 00007ffcf3bec288 The buggy address belongs to the page: page:ffffea0001657d40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x595f5 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001704108 ffffea0001303208 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 11627, ts 506522118583, free_ts 508455699710 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146 shmem_alloc_page mm/shmem.c:1586 [inline] shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1611 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1906 shmem_fault+0x1d7/0x700 mm/shmem.c:2118 __do_fault+0x139/0x340 mm/memory.c:3926 do_read_fault mm/memory.c:4262 [inline] do_fault mm/memory.c:4390 [inline] handle_pte_fault mm/memory.c:4648 [inline] __handle_mm_fault mm/memory.c:4783 [inline] handle_mm_fault+0x376f/0x5960 mm/memory.c:4881 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:556 ksys_mmap_pgoff+0x13e/0x780 mm/mmap.c:1623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 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:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 __pagevec_release+0x80/0xf0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145 evict+0x529/0x930 fs/inode.c:622 __dentry_kill+0x436/0x650 fs/dcache.c:586 dentry_kill+0xbb/0x290 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x636/0x8e0 fs/file_table.c:288 task_work_run+0x129/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x6a3/0x2480 kernel/exit.c:874 do_group_exit+0x144/0x310 kernel/exit.c:996 __do_sys_exit_group kernel/exit.c:1007 [inline] __se_sys_exit_group kernel/exit.c:1005 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff8880595f5000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880595f5080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880595f5100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880595f5180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880595f5200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================