Buffer I/O error on dev loop3, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x10d9/0x1270 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff8880682851ce by task syz.3.8/4407 CPU: 1 PID: 4407 Comm: syz.3.8 Not tainted 6.1.144-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x220 mm/kasan/report.c:427 kasan_report+0x10b/0x140 mm/kasan/report.c:531 sysv_new_inode+0x10d9/0x1270 fs/sysv/ialloc.c:153 sysv_mknod+0x4a/0xd0 fs/sysv/namei.c:53 vfs_create+0x2db/0x460 fs/namei.c:3184 do_mknodat+0x399/0x4c0 fs/namei.c:4035 __do_sys_mknodat fs/namei.c:4063 [inline] __se_sys_mknodat fs/namei.c:4060 [inline] __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:4060 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd4d758e929 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:00007fd4d8388038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103 RAX: ffffffffffffffda RBX: 00007fd4d77b5fa0 RCX: 00007fd4d758e929 RDX: 00000000000081c0 RSI: 00002000000000c0 RDI: ffffffffffffff9c RBP: 00007fd4d7610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd4d77b5fa0 R15: 00007ffed4e0f2b8 The buggy address belongs to the physical page: page:ffffea0001a0a140 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x68285 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001a0a008 ffffea0001a0a108 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 4396, tgid 4395 (syz.3.4), ts 88002796827, free_ts 88920169464 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 __folio_alloc+0xe/0x30 mm/page_alloc.c:5646 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243 shmem_alloc_folio mm/shmem.c:1589 [inline] shmem_alloc_and_acct_folio+0x42e/0xb60 mm/shmem.c:1613 shmem_get_folio_gfp+0x1361/0x3400 mm/shmem.c:1941 shmem_fault+0x1be/0x7b0 mm/shmem.c:2156 __do_fault+0x13b/0x4e0 mm/memory.c:4280 do_read_fault mm/memory.c:4631 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x28ca/0x3e70 mm/memory.c:5294 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x3ff/0xeb0 mm/gup.c:1250 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607 __mm_populate+0x248/0x370 mm/gup.c:1721 mm_populate include/linux/mm.h:2826 [inline] vm_mmap_pgoff+0x203/0x2b0 mm/util.c:525 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525 release_pages+0x1f92/0x2200 mm/swap.c:1035 __pagevec_release+0x6d/0xe0 mm/swap.c:1055 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x75b/0x2050 mm/shmem.c:946 shmem_truncate_range mm/shmem.c:1062 [inline] shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171 evict+0x485/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfa/0x1d0 fs/dcache.c:918 __fput+0x5e0/0x920 fs/file_table.c:328 task_work_run+0x1ca/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x93e/0x2400 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 Memory state around the buggy address: ffff888068285080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888068285100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888068285180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888068285200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888068285280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 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