| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-41083: netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid |
| |
| Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has |
| taken the folio lock (as filemap_page_mkwrite() does). Without this, |
| generic/247 occasionally oopses with something like the following: |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| #PF: supervisor read access in kernel mode |
| #PF: error_code(0x0000) - not-present page |
| |
| RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0 |
| ... |
| Call Trace: |
| <TASK> |
| ? __die_body+0x1a/0x60 |
| ? page_fault_oops+0x6e/0xa0 |
| ? exc_page_fault+0xc2/0xe0 |
| ? asm_exc_page_fault+0x22/0x30 |
| ? trace_event_raw_event_netfs_folio+0x61/0xc0 |
| trace_netfs_folio+0x39/0x40 |
| netfs_page_mkwrite+0x14c/0x1d0 |
| do_page_mkwrite+0x50/0x90 |
| do_pte_missing+0x184/0x200 |
| __handle_mm_fault+0x42d/0x500 |
| handle_mm_fault+0x121/0x1f0 |
| do_user_addr_fault+0x23e/0x3c0 |
| exc_page_fault+0xc2/0xe0 |
| asm_exc_page_fault+0x22/0x30 |
| |
| This is due to the invalidate_inode_pages2_range() issued at the end of the |
| DIO write interfering with the mmap'd writes. |
| |
| The Linux kernel CVE team has assigned CVE-2024-41083 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.8 with commit 102a7e2c598c22bd2621fa97eb1c93c89d469a12 and fixed in 6.9.8 with commit 3473eb87afd402e415a8ca885b284ea0420dde25 |
| Issue introduced in 6.8 with commit 102a7e2c598c22bd2621fa97eb1c93c89d469a12 and fixed in 6.10 with commit a81c98bfa40c11f8ea79b5a9b3f5fda73bfbb4d2 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-41083 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/netfs/buffered_write.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/3473eb87afd402e415a8ca885b284ea0420dde25 |
| https://git.kernel.org/stable/c/a81c98bfa40c11f8ea79b5a9b3f5fda73bfbb4d2 |
