| 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-2024-50073: tty: n_gsm: Fix use-after-free in gsm_cleanup_mux |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tty: n_gsm: Fix use-after-free in gsm_cleanup_mux |
| |
| BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0 |
| drivers/tty/n_gsm.c:3160 [n_gsm] |
| Read of size 8 at addr ffff88815fe99c00 by task poc/3379 |
| CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56 |
| Hardware name: VMware, Inc. VMware Virtual Platform/440BX |
| Desktop Reference Platform, BIOS 6.00 11/12/2020 |
| Call Trace: |
| <TASK> |
| gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] |
| __pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm] |
| __pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389 |
| update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500 |
| __pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846 |
| __rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161 |
| gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] |
| _raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107 |
| __pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm] |
| ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195 |
| ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79 |
| __pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338 |
| __pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805 |
| tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 |
| |
| Allocated by task 65: |
| gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm] |
| gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm] |
| gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm] |
| gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm] |
| tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391 |
| tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39 |
| flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445 |
| process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229 |
| worker_thread+0x3dc/0x950 kernel/workqueue.c:3391 |
| kthread+0x2a3/0x370 kernel/kthread.c:389 |
| ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147 |
| ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257 |
| |
| Freed by task 3367: |
| kfree+0x126/0x420 mm/slub.c:4580 |
| gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] |
| gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] |
| tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 |
| |
| [Analysis] |
| gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux |
| can be freed by multi threads through ioctl,which leads |
| to the occurrence of uaf. Protect it by gsm tx lock. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50073 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 6.1.114 with commit bf171b5e86e41de4c1cf32fb7aefa275c3d7de49 |
| Fixed in 6.6.58 with commit c29f192e0d44cc1cbaf698fa1ff198f63556691a |
| Fixed in 6.11.5 with commit 0eec592c6a7460ba795d7de29f3dc95cb5422e62 |
| Fixed in 6.12 with commit 9462f4ca56e7d2430fdb6dcc8498244acbfc4489 |
| |
| 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-2024-50073 |
| 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/tty/n_gsm.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/bf171b5e86e41de4c1cf32fb7aefa275c3d7de49 |
| https://git.kernel.org/stable/c/c29f192e0d44cc1cbaf698fa1ff198f63556691a |
| https://git.kernel.org/stable/c/0eec592c6a7460ba795d7de29f3dc95cb5422e62 |
| https://git.kernel.org/stable/c/9462f4ca56e7d2430fdb6dcc8498244acbfc4489 |
