| 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-2024-56670: usb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| usb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer |
| |
| Considering that in some extreme cases, |
| when u_serial driver is accessed by multiple threads, |
| Thread A is executing the open operation and calling the gs_open, |
| Thread B is executing the disconnect operation and calling the |
| gserial_disconnect function,The port->port_usb pointer will be set to NULL. |
| |
| E.g. |
| Thread A Thread B |
| gs_open() gadget_unbind_driver() |
| gs_start_io() composite_disconnect() |
| gs_start_rx() gserial_disconnect() |
| ... ... |
| spin_unlock(&port->port_lock) |
| status = usb_ep_queue() spin_lock(&port->port_lock) |
| spin_lock(&port->port_lock) port->port_usb = NULL |
| gs_free_requests(port->port_usb->in) spin_unlock(&port->port_lock) |
| Crash |
| |
| This causes thread A to access a null pointer (port->port_usb is null) |
| when calling the gs_free_requests function, causing a crash. |
| |
| If port_usb is NULL, the release request will be skipped as it |
| will be done by gserial_disconnect. |
| |
| So add a null pointer check to gs_start_io before attempting |
| to access the value of the pointer port->port_usb. |
| |
| Call trace: |
| gs_start_io+0x164/0x25c |
| gs_open+0x108/0x13c |
| tty_open+0x314/0x638 |
| chrdev_open+0x1b8/0x258 |
| do_dentry_open+0x2c4/0x700 |
| vfs_open+0x2c/0x3c |
| path_openat+0xa64/0xc60 |
| do_filp_open+0xb8/0x164 |
| do_sys_openat2+0x84/0xf0 |
| __arm64_sys_openat+0x70/0x9c |
| invoke_syscall+0x58/0x114 |
| el0_svc_common+0x80/0xe0 |
| do_el0_svc+0x1c/0x28 |
| el0_svc+0x38/0x68 |
| |
| The Linux kernel CVE team has assigned CVE-2024-56670 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 5.4.288 with commit 4efdfdc32d8d6307f968cd99f1db64468471bab1 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 5.10.232 with commit 28b3c03a6790de1f6f2683919ad657840f0f0f58 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 5.15.175 with commit 1247e1df086aa6c17ab53cd1bedce70dd7132765 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 6.1.121 with commit c83213b6649d22656b3a4e92544ceeea8a2c6c07 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 6.6.67 with commit 8ca07a3d18f39b1669927ef536e485787e856df6 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 6.12.6 with commit dd6b0ca6025f64ccb465a6a3460c5b0307ed9c44 |
| Issue introduced in 2.6.27 with commit c1dca562be8ada614ef193aa246c6f8705bcd6b9 and fixed in 6.13 with commit 4cfbca86f6a8b801f3254e0e3c8f2b1d2d64be2b |
| |
| 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-2024-56670 |
| 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/usb/gadget/function/u_serial.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/4efdfdc32d8d6307f968cd99f1db64468471bab1 |
| https://git.kernel.org/stable/c/28b3c03a6790de1f6f2683919ad657840f0f0f58 |
| https://git.kernel.org/stable/c/1247e1df086aa6c17ab53cd1bedce70dd7132765 |
| https://git.kernel.org/stable/c/c83213b6649d22656b3a4e92544ceeea8a2c6c07 |
| https://git.kernel.org/stable/c/8ca07a3d18f39b1669927ef536e485787e856df6 |
| https://git.kernel.org/stable/c/dd6b0ca6025f64ccb465a6a3460c5b0307ed9c44 |
| https://git.kernel.org/stable/c/4cfbca86f6a8b801f3254e0e3c8f2b1d2d64be2b |
