| 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-2023-52468: class: fix use-after-free in class_register() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| class: fix use-after-free in class_register() |
| |
| The lock_class_key is still registered and can be found in |
| lock_keys_hash hlist after subsys_private is freed in error |
| handler path.A task who iterate over the lock_keys_hash |
| later may cause use-after-free.So fix that up and unregister |
| the lock_class_key before kfree(cp). |
| |
| On our platform, a driver fails to kset_register because of |
| creating duplicate filename '/class/xxx'.With Kasan enabled, |
| it prints a invalid-access bug report. |
| |
| KASAN bug report: |
| |
| BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc |
| Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252 |
| Pointer tag: [15], memory tag: [fe] |
| |
| CPU: 7 PID: 252 Comm: modprobe Tainted: G W |
| 6.6.0-mainline-maybe-dirty #1 |
| |
| Call trace: |
| dump_backtrace+0x1b0/0x1e4 |
| show_stack+0x2c/0x40 |
| dump_stack_lvl+0xac/0xe0 |
| print_report+0x18c/0x4d8 |
| kasan_report+0xe8/0x148 |
| __hwasan_store8_noabort+0x88/0x98 |
| lockdep_register_key+0x19c/0x1bc |
| class_register+0x94/0x1ec |
| init_module+0xbc/0xf48 [rfkill] |
| do_one_initcall+0x17c/0x72c |
| do_init_module+0x19c/0x3f8 |
| ... |
| Memory state around the buggy address: |
| ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a |
| ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe |
| >ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe |
| ^ |
| ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 |
| |
| As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access |
| not use-after-free here.In this case, modprobe is manipulating |
| the corrupted lock_keys_hash hlish where lock_class_key is already |
| freed before. |
| |
| It's worth noting that this only can happen if lockdep is enabled, |
| which is not true for normal system. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52468 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit dcfbb67e48a2becfce7990386e985b9c45098ee5 and fixed in 6.6.14 with commit b57196a5ec5e4c0ffecde8348b085b778c7dce04 |
| Issue introduced in 6.4 with commit dcfbb67e48a2becfce7990386e985b9c45098ee5 and fixed in 6.7.2 with commit 0f1486dafca3398c4c46b9f6e6452fa27e73b559 |
| Issue introduced in 6.4 with commit dcfbb67e48a2becfce7990386e985b9c45098ee5 and fixed in 6.8 with commit 93ec4a3b76404bce01bd5c9032bef5df6feb1d62 |
| |
| 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-2023-52468 |
| 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: |
| drivers/base/class.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/b57196a5ec5e4c0ffecde8348b085b778c7dce04 |
| https://git.kernel.org/stable/c/0f1486dafca3398c4c46b9f6e6452fa27e73b559 |
| https://git.kernel.org/stable/c/93ec4a3b76404bce01bd5c9032bef5df6feb1d62 |
