CVE-2023-52741

Linux kernel-də aşağıdakı zəiflik aradan qaldırılmışdır: cifs: rdata->read_into_pages() funksiyasında use-after-free xətası düzəldildi Şəbəkə vəziyyəti qeyri-stabil olduqda, serverdən məlumat oxunan zaman use-after-free baş verə bilər. BUG: KASAN: use-after-free in readpages_fill_pages+0x14c/0x7e0 Call Trace: <TASK> dump_stack_lvl+0x38/0x4c print_report+0x16f/0x4a6 kasan_report+0xb7/0x130 readpages_fill_pages+0x14c/0x7e0 cifs_readv_receive+0x46d/0xa40 cifs_demultiplex_thread+0x121c/0x1490 kthread+0x16b/0x1a0 ret_from_fork+0x2c/0x50 </TASK> Allocated by task 2535: kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x82/0x90 cifs_readdata_direct_alloc+0x2c/0x110 cifs_readdata_alloc+0x2d/0x60 cifs_readahead+0x393/0xfe0 read_pages+0x12f/0x470 page_cache_ra_unbounded+0x1b1/0x240 filemap_get_pages+0x1c8/0x9a0 filemap_read+0x1c0/0x540 cifs_strict_readv+0x21b/0x240 vfs_read+0x395/0x4b0 ksys_read+0xb8/0x150 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Freed by task 79: kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2e/0x50 __kasan_slab_free+0x10e/0x1a0 __kmem_cache_free+0x7a/0x1a0 cifs_readdata_release+0x49/0x60 process_one_work+0x46c/0x760 worker_thread+0x2a4/0x6f0 kthread+0x16b/0x1a0 ret_from_fork+0x2c/0x50 Last potentially related work creation: kasan_save_stack+0x22/0x50 __kasan_record_aux_stack+0x95/0xb0 insert_work+0x2b/0x130 __queue_work+0x1fe/0x660 queue_work_on+0x4b/0x60 smb2_readv_callback+0x396/0x800 cifs_abort_connection+0x474/0x6a0 cifs_reconnect+0x5cb/0xa50 cifs_readv_from_socket.cold+0x22/0x6c cifs_read_page_from_socket+0xc1/0x100 readpages_fill_pages.cold+0x2f/0x46 cifs_readv_receive+0x46d/0xa40 cifs_demultiplex_thread+0x121c/0x1490 kthread+0x16b/0x1a0 ret_from_fork+0x2c/0x50 Aşağıdakı funksiya çağırışları rdata göstərəcinin UAF-na səbəb olacaqdır. readpages_fill_pages cifs_read_page_from_socket cifs_readv_from_socket cifs_reconnect __cifs_reconnect cifs_abort_connection mid->callback() --> smb2_readv_callback queue_work(&rdata->work) # əgər işçi (worker) daha tez tamamlanarsa, # rdata azad edilir cifs_readv_complete kref_put cifs_readdata_release kfree(rdata) return rdata->... # readpages_fill_pages()-da UAF Bənzər şəkildə bu problem uncache_fill_pages()-da da baş verir. Bu problem geri dönüş operatorundakı şərt yoxlamasının ardıcıllığı tənzimlənməklə həll edilmişdir.