| 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-2024-26895: wifi: wilc1000: prevent use-after-free on vif when cleaning up all interfaces |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| wifi: wilc1000: prevent use-after-free on vif when cleaning up all interfaces |
| |
| wilc_netdev_cleanup currently triggers a KASAN warning, which can be |
| observed on interface registration error path, or simply by |
| removing the module/unbinding device from driver: |
| |
| echo spi0.1 > /sys/bus/spi/drivers/wilc1000_spi/unbind |
| |
| ================================================================== |
| BUG: KASAN: slab-use-after-free in wilc_netdev_cleanup+0x508/0x5cc |
| Read of size 4 at addr c54d1ce8 by task sh/86 |
| |
| CPU: 0 PID: 86 Comm: sh Not tainted 6.8.0-rc1+ #117 |
| Hardware name: Atmel SAMA5 |
| unwind_backtrace from show_stack+0x18/0x1c |
| show_stack from dump_stack_lvl+0x34/0x58 |
| dump_stack_lvl from print_report+0x154/0x500 |
| print_report from kasan_report+0xac/0xd8 |
| kasan_report from wilc_netdev_cleanup+0x508/0x5cc |
| wilc_netdev_cleanup from wilc_bus_remove+0xc8/0xec |
| wilc_bus_remove from spi_remove+0x8c/0xac |
| spi_remove from device_release_driver_internal+0x434/0x5f8 |
| device_release_driver_internal from unbind_store+0xbc/0x108 |
| unbind_store from kernfs_fop_write_iter+0x398/0x584 |
| kernfs_fop_write_iter from vfs_write+0x728/0xf88 |
| vfs_write from ksys_write+0x110/0x1e4 |
| ksys_write from ret_fast_syscall+0x0/0x1c |
| |
| [...] |
| |
| Allocated by task 1: |
| kasan_save_track+0x30/0x5c |
| __kasan_kmalloc+0x8c/0x94 |
| __kmalloc_node+0x1cc/0x3e4 |
| kvmalloc_node+0x48/0x180 |
| alloc_netdev_mqs+0x68/0x11dc |
| alloc_etherdev_mqs+0x28/0x34 |
| wilc_netdev_ifc_init+0x34/0x8ec |
| wilc_cfg80211_init+0x690/0x910 |
| wilc_bus_probe+0xe0/0x4a0 |
| spi_probe+0x158/0x1b0 |
| really_probe+0x270/0xdf4 |
| __driver_probe_device+0x1dc/0x580 |
| driver_probe_device+0x60/0x140 |
| __driver_attach+0x228/0x5d4 |
| bus_for_each_dev+0x13c/0x1a8 |
| bus_add_driver+0x2a0/0x608 |
| driver_register+0x24c/0x578 |
| do_one_initcall+0x180/0x310 |
| kernel_init_freeable+0x424/0x484 |
| kernel_init+0x20/0x148 |
| ret_from_fork+0x14/0x28 |
| |
| Freed by task 86: |
| kasan_save_track+0x30/0x5c |
| kasan_save_free_info+0x38/0x58 |
| __kasan_slab_free+0xe4/0x140 |
| kfree+0xb0/0x238 |
| device_release+0xc0/0x2a8 |
| kobject_put+0x1d4/0x46c |
| netdev_run_todo+0x8fc/0x11d0 |
| wilc_netdev_cleanup+0x1e4/0x5cc |
| wilc_bus_remove+0xc8/0xec |
| spi_remove+0x8c/0xac |
| device_release_driver_internal+0x434/0x5f8 |
| unbind_store+0xbc/0x108 |
| kernfs_fop_write_iter+0x398/0x584 |
| vfs_write+0x728/0xf88 |
| ksys_write+0x110/0x1e4 |
| ret_fast_syscall+0x0/0x1c |
| [...] |
| |
| David Mosberger-Tan initial investigation [1] showed that this |
| use-after-free is due to netdevice unregistration during vif list |
| traversal. When unregistering a net device, since the needs_free_netdev has |
| been set to true during registration, the netdevice object is also freed, |
| and as a consequence, the corresponding vif object too, since it is |
| attached to it as private netdevice data. The next occurrence of the loop |
| then tries to access freed vif pointer to the list to move forward in the |
| list. |
| |
| Fix this use-after-free thanks to two mechanisms: |
| - navigate in the list with list_for_each_entry_safe, which allows to |
| safely modify the list as we go through each element. For each element, |
| remove it from the list with list_del_rcu |
| - make sure to wait for RCU grace period end after each vif removal to make |
| sure it is safe to free the corresponding vif too (through |
| unregister_netdev) |
| |
| Since we are in a RCU "modifier" path (not a "reader" path), and because |
| such path is expected not to be concurrent to any other modifier (we are |
| using the vif_mutex lock), we do not need to use RCU list API, that's why |
| we can benefit from list_for_each_entry_safe. |
| |
| [1] https://lore.kernel.org/linux-wireless/ab077dbe58b1ea5de0a3b2ca21f275a07af967d2.camel@egauge.net/ |
| |
| The Linux kernel CVE team has assigned CVE-2024-26895 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 5.10.214 with commit 5956f4203b6cdd0755bbdd21b45f3933c7026208 |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 5.15.153 with commit fe20e3d56bc911408fc3c27a17c59e9d7885f7d1 |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 6.1.83 with commit a9545af2a533739ffb64d6c9a6fec6f13e2b505f |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 6.6.23 with commit 3da9d32b7f4a1a9f7e4bb15bb82f2b2dd6719447 |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 6.7.11 with commit 24228dcf1d30c2231caa332be7d3090ac59fbfe9 |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 6.8.2 with commit 73a2aa0aef86c2c07be5a2f42c9e6047e1a2f7bb |
| Issue introduced in 5.5 with commit 8399918f3056e1033f0f4c08eab437fb38d6f22d and fixed in 6.9 with commit cb5942b77c05d54310a0420cac12935e9b6aa21c |
| |
| 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-2024-26895 |
| 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/net/wireless/microchip/wilc1000/netdev.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/5956f4203b6cdd0755bbdd21b45f3933c7026208 |
| https://git.kernel.org/stable/c/fe20e3d56bc911408fc3c27a17c59e9d7885f7d1 |
| https://git.kernel.org/stable/c/a9545af2a533739ffb64d6c9a6fec6f13e2b505f |
| https://git.kernel.org/stable/c/3da9d32b7f4a1a9f7e4bb15bb82f2b2dd6719447 |
| https://git.kernel.org/stable/c/24228dcf1d30c2231caa332be7d3090ac59fbfe9 |
| https://git.kernel.org/stable/c/73a2aa0aef86c2c07be5a2f42c9e6047e1a2f7bb |
| https://git.kernel.org/stable/c/cb5942b77c05d54310a0420cac12935e9b6aa21c |
