================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff8880573fd1ce by task syz.1.778/8185 CPU: 0 PID: 8185 Comm: syz.1.778 Not tainted 6.10.0-rc7-syzkaller-00254-g528dd46d0fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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+0xfd3/0x1170 fs/sysv/ialloc.c:153 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3505 [inline] open_last_lookups fs/namei.c:3574 [inline] path_openat+0x1a86/0x35f0 fs/namei.c:3810 do_filp_open+0x235/0x490 fs/namei.c:3840 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413 do_sys_open fs/open.c:1428 [inline] __do_sys_openat fs/open.c:1444 [inline] __se_sys_openat fs/open.c:1439 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1439 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: 0033:0x7fdd31575bd9 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:00007fdd32373048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fdd31703f60 RCX: 00007fdd31575bd9 RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c RBP: 00007fdd315e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fdd31703f60 R15: 00007ffcfe82f618 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x36c pfn:0x573fd flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 000000000000036c 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 15634, tgid 15633 (syz.2.3138), ts 987178937286, free_ts 991232497380 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473 prep_new_page mm/page_alloc.c:1481 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 shmem_alloc_folio mm/shmem.c:1639 [inline] shmem_alloc_and_add_folio+0x24d/0xdb0 mm/shmem.c:1679 shmem_get_folio_gfp+0x82d/0x1f50 mm/shmem.c:2066 shmem_get_folio mm/shmem.c:2171 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2754 generic_perform_write+0x324/0x640 mm/filemap.c:4016 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2930 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa74/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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 11502 tgid 11502 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1093 [inline] free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2637 folios_put_refs+0x93a/0xa60 mm/swap.c:1024 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x6de/0x1df0 mm/shmem.c:1016 shmem_truncate_range mm/shmem.c:1125 [inline] shmem_evict_inode+0x29b/0xa60 mm/shmem.c:1253 evict+0x2aa/0x630 fs/inode.c:667 __dentry_kill+0x20d/0x630 fs/dcache.c:607 dput+0x19f/0x2b0 fs/dcache.c:849 __fput+0x5f8/0x8a0 fs/file_table.c:430 task_work_run+0x251/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x360 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880573fd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880573fd100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880573fd180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880573fd200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880573fd280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================