================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88806cfc21ce by task syz.3.18/6050 CPU: 0 UID: 0 PID: 6050 Comm: syz.3.18 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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 sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3595 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_open fs/open.c:1438 [inline] __se_sys_open fs/open.c:1434 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1434 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: 0033:0x7f1d0d97e719 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:00007f1d0e779038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f1d0db35f80 RCX: 00007f1d0d97e719 RDX: 0000000000000124 RSI: 0000000000004042 RDI: 0000000020000140 RBP: 00007f1d0d9f139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1d0db35f80 R15: 00007ffd14e8f688 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x75381 pfn:0x6cfc2 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000075381 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 6072, tgid 6071 (syz.4.19), ts 540742603191, free_ts 581309631205 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3033/0x3180 mm/page_alloc.c:3457 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_pages_noprof mm/mempolicy.c:2345 [inline] folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010 do_read_cache_folio+0x2eb/0x850 mm/filemap.c:3787 read_mapping_folio include/linux/pagemap.h:1011 [inline] dir_get_folio fs/sysv/dir.c:64 [inline] sysv_find_entry+0x16a/0x4b0 fs/sysv/dir.c:154 sysv_inode_by_name+0x98/0x2a0 fs/sysv/dir.c:370 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38 lookup_open fs/namei.c:3573 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x11a7/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_open fs/open.c:1438 [inline] __se_sys_open fs/open.c:1434 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1434 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 6072 tgid 6071 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_folios+0xee2/0x18a0 mm/page_alloc.c:2686 folios_put_refs+0x76c/0x860 mm/swap.c:1007 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x47b/0xfc0 mm/truncate.c:346 sysv_evict_inode+0x2b/0x110 fs/sysv/inode.c:289 evict+0x4e8/0x9b0 fs/inode.c:725 __dentry_kill+0x20d/0x630 fs/dcache.c:615 dput+0x19f/0x2b0 fs/dcache.c:857 shrink_dcache_for_umount+0xb4/0x180 fs/dcache.c:1567 generic_shutdown_super+0x6a/0x2d0 fs/super.c:620 kill_block_super+0x44/0x90 fs/super.c:1710 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 Memory state around the buggy address: ffff88806cfc2080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806cfc2100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88806cfc2180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88806cfc2200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806cfc2280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================