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BUG: KASAN: use-after-free in vma_pages include/linux/mm.h:2838 [inline]
BUG: KASAN: use-after-free in vma_last_pgoff mm/interval_tree.c:20 [inline]
BUG: KASAN: use-after-free in vma_interval_tree_augment_compute_max mm/interval_tree.c:25 [inline]
BUG: KASAN: use-after-free in vma_interval_tree_augment_rotate+0xb1/0x1e0 mm/interval_tree.c:23
Read of size 8 at addr ffff8881bfffffb0 by task syz-executor/1208

CPU: 1 PID: 1208 Comm: syz-executor Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 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+0x10f/0x150 mm/kasan/report.c:444
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 vma_pages include/linux/mm.h:2838 [inline]
 vma_last_pgoff mm/interval_tree.c:20 [inline]
 vma_interval_tree_augment_compute_max mm/interval_tree.c:25 [inline]
 vma_interval_tree_augment_rotate+0xb1/0x1e0 mm/interval_tree.c:23
 __rb_insert lib/rbtree.c:-1 [inline]
 __rb_insert_augmented+0x6ac/0x6f0 lib/rbtree.c:459
 rb_insert_augmented include/linux/rbtree_augmented.h:50 [inline]
 vma_interval_tree_insert_after+0x2a6/0x2c0 mm/interval_tree.c:57
 dup_mmap kernel/fork.c:635 [inline]
 dup_mm kernel/fork.c:1527 [inline]
 copy_mm+0xb34/0x13a0 kernel/fork.c:1579
 copy_process+0x1184/0x3280 kernel/fork.c:2353
 kernel_clone+0x233/0x960 kernel/fork.c:2742
 __do_sys_clone kernel/fork.c:2868 [inline]
 __se_sys_clone kernel/fork.c:2852 [inline]
 __x64_sys_clone+0x198/0x210 kernel/fork.c:2852
 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 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
RIP: 0033:0x7f11fbe47a92
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd57a1d340 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd57a1d340 RCX: 00007f11fbe47a92
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd57a1d4cc R08: 0000000000000000 R09: 0000000000000001
R10: 000055555917a7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001fae7 R15: 00007ffd57a1d520
 </TASK>

The buggy address belongs to the page:
page:ffffea0006ffffc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x100 pfn:0x1bffff
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000100 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 3961, ts 118474568141, free_ts 120480526580
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
 __alloc_pages_node include/linux/gfp.h:595 [inline]
 alloc_pages_node include/linux/gfp.h:609 [inline]
 alloc_pages include/linux/gfp.h:622 [inline]
 shmem_alloc_page mm/shmem.c:1587 [inline]
 shmem_alloc_and_acct_page+0x4a2/0x8d0 mm/shmem.c:1612
 shmem_getpage_gfp+0x127d/0x2250 mm/shmem.c:1908
 shmem_getpage mm/shmem.c:152 [inline]
 shmem_write_begin+0xce/0x1b0 mm/shmem.c:2476
 generic_perform_write+0x2b7/0x690 mm/filemap.c:3887
 __generic_file_write_iter+0x268/0x490 mm/filemap.c:4015
 generic_file_write_iter+0xa9/0x1d0 mm/filemap.c:4047
 __kernel_write+0x521/0x970 fs/read_write.c:539
 __dump_emit+0x255/0x380 fs/coredump.c:880
 dump_emit+0x36a/0x3d0 fs/coredump.c:917
 dump_user_range+0x86/0x1c0 fs/coredump.c:954
 elf_core_dump+0x2aa4/0x2ff0 fs/binfmt_elf.c:2285
 do_coredump+0x13c2/0x27d0 fs/coredump.c:831
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1474 [inline]
 free_pcp_prepare mm/page_alloc.c:1546 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
 free_unref_page_list+0x138/0x9e0 mm/page_alloc.c:3673
 release_pages+0x1264/0x12c0 mm/swap.c:1015
 __pagevec_release+0x71/0xe0 mm/swap.c:1035
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x564/0x13b0 mm/shmem.c:965
 shmem_truncate_range mm/shmem.c:1064 [inline]
 shmem_evict_inode+0x1dc/0x970 mm/shmem.c:1146
 evict+0x4b6/0x8b0 fs/inode.c:650
 iput_final fs/inode.c:1779 [inline]
 iput+0x651/0x7e0 fs/inode.c:1805
 dentry_unlink_inode+0x338/0x3e0 fs/dcache.c:380
 __dentry_kill+0x45b/0x660 fs/dcache.c:586
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x47/0x90 fs/dcache.c:893
 __fput+0x5c7/0x900 fs/file_table.c:319
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xb70/0x29a0 kernel/exit.c:890

Memory state around the buggy address:
 ffff8881bffffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881bfffff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881bfffff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff8881c0000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881c0000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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