| 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-2021-47202: thermal: Fix NULL pointer dereferences in of_thermal_ functions |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| thermal: Fix NULL pointer dereferences in of_thermal_ functions |
| |
| of_parse_thermal_zones() parses the thermal-zones node and registers a |
| thermal_zone device for each subnode. However, if a thermal zone is |
| consuming a thermal sensor and that thermal sensor device hasn't probed |
| yet, an attempt to set trip_point_*_temp for that thermal zone device |
| can cause a NULL pointer dereference. Fix it. |
| |
| console:/sys/class/thermal/thermal_zone87 # echo 120000 > trip_point_0_temp |
| ... |
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 |
| ... |
| Call trace: |
| of_thermal_set_trip_temp+0x40/0xc4 |
| trip_point_temp_store+0xc0/0x1dc |
| dev_attr_store+0x38/0x88 |
| sysfs_kf_write+0x64/0xc0 |
| kernfs_fop_write_iter+0x108/0x1d0 |
| vfs_write+0x2f4/0x368 |
| ksys_write+0x7c/0xec |
| __arm64_sys_write+0x20/0x30 |
| el0_svc_common.llvm.7279915941325364641+0xbc/0x1bc |
| do_el0_svc+0x28/0xa0 |
| el0_svc+0x14/0x24 |
| el0_sync_handler+0x88/0xec |
| el0_sync+0x1c0/0x200 |
| |
| While at it, fix the possible NULL pointer dereference in other |
| functions as well: of_thermal_get_temp(), of_thermal_set_emul_temp(), |
| of_thermal_get_trend(). |
| |
| The Linux kernel CVE team has assigned CVE-2021-47202 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.4.210 with commit 828f4c31684da94ecf0b44a2cbd35bbede04f0bd |
| Fixed in 5.10.81 with commit 6a315471cb6a07f651e1d3adc8962730f4fcccac |
| Fixed in 5.14.21 with commit 0750f769b95841b34a9fe8c418dd792ff526bf86 |
| Fixed in 5.15.4 with commit ef2590a5305e0b8e9342f84c2214aa478ee7f28e |
| Fixed in 5.16 with commit 96cfe05051fd8543cdedd6807ec59a0e6c409195 |
| |
| 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-2021-47202 |
| 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/thermal/thermal_of.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/828f4c31684da94ecf0b44a2cbd35bbede04f0bd |
| https://git.kernel.org/stable/c/6a315471cb6a07f651e1d3adc8962730f4fcccac |
| https://git.kernel.org/stable/c/0750f769b95841b34a9fe8c418dd792ff526bf86 |
| https://git.kernel.org/stable/c/ef2590a5305e0b8e9342f84c2214aa478ee7f28e |
| https://git.kernel.org/stable/c/96cfe05051fd8543cdedd6807ec59a0e6c409195 |
