CVE-2024-41083

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfs: Fix netfs_page_mkwrite() to check folio-&gt;mapping is valid<br /> <br /> Fix netfs_page_mkwrite() to check that folio-&gt;mapping is valid once it has<br /> taken the folio lock (as filemap_page_mkwrite() does). Without this,<br /> generic/247 occasionally oopses with something like the following:<br /> <br /> BUG: kernel NULL pointer dereference, address: 0000000000000000<br /> #PF: supervisor read access in kernel mode<br /> #PF: error_code(0x0000) - not-present page<br /> <br /> RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0<br /> ...<br /> Call Trace:<br /> <br /> ? __die_body+0x1a/0x60<br /> ? page_fault_oops+0x6e/0xa0<br /> ? exc_page_fault+0xc2/0xe0<br /> ? asm_exc_page_fault+0x22/0x30<br /> ? trace_event_raw_event_netfs_folio+0x61/0xc0<br /> trace_netfs_folio+0x39/0x40<br /> netfs_page_mkwrite+0x14c/0x1d0<br /> do_page_mkwrite+0x50/0x90<br /> do_pte_missing+0x184/0x200<br /> __handle_mm_fault+0x42d/0x500<br /> handle_mm_fault+0x121/0x1f0<br /> do_user_addr_fault+0x23e/0x3c0<br /> exc_page_fault+0xc2/0xe0<br /> asm_exc_page_fault+0x22/0x30<br /> <br /> This is due to the invalidate_inode_pages2_range() issued at the end of the<br /> DIO write interfering with the mmap&amp;#39;d writes.