From bippy-1e70cc10feda Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman To: Reply-to: , Subject: CVE-2021-46979: iio: core: fix ioctl handlers removal Description =========== In the Linux kernel, the following vulnerability has been resolved: iio: core: fix ioctl handlers removal Currently ioctl handlers are removed twice. For the first time during iio_device_unregister() then later on inside iio_device_unregister_eventset() and iio_buffers_free_sysfs_and_mask(). Double free leads to kernel panic. Fix this by not touching ioctl handlers list directly but rather letting code responsible for registration call the matching cleanup routine itself. The Linux kernel CVE team has assigned CVE-2021-46979 to this issue. Affected and fixed versions =========================== Issue introduced in 5.11 with commit 8dedcc3eee3a and fixed in 5.11.22 with commit 11e1cae5da40 Issue introduced in 5.11 with commit 8dedcc3eee3a and fixed in 5.12.5 with commit ab6c935ba3a0 Issue introduced in 5.11 with commit 8dedcc3eee3a and fixed in 5.13 with commit 901f84de0e16 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-2021-46979 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/iio/industrialio-core.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/11e1cae5da4096552f7c091476cbadbc0d1817da https://git.kernel.org/stable/c/ab6c935ba3a04317632f3b8b68675bdbaf395303 https://git.kernel.org/stable/c/901f84de0e16bde10a72d7eb2f2eb73fcde8fa1a