CVE-2022-50206

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> arm64: fix oops in concurrently setting insn_emulation sysctls<br /> <br /> emulation_proc_handler() changes table-&gt;data for proc_dointvec_minmax<br /> and can generate the following Oops if called concurrently with itself:<br /> <br /> | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010<br /> | Internal error: Oops: 96000006 [#1] SMP<br /> | Call trace:<br /> | update_insn_emulation_mode+0xc0/0x148<br /> | emulation_proc_handler+0x64/0xb8<br /> | proc_sys_call_handler+0x9c/0xf8<br /> | proc_sys_write+0x18/0x20<br /> | __vfs_write+0x20/0x48<br /> | vfs_write+0xe4/0x1d0<br /> | ksys_write+0x70/0xf8<br /> | __arm64_sys_write+0x20/0x28<br /> | el0_svc_common.constprop.0+0x7c/0x1c0<br /> | el0_svc_handler+0x2c/0xa0<br /> | el0_svc+0x8/0x200<br /> <br /> To fix this issue, keep the table-&gt;data as &amp;insn-&gt;current_mode and<br /> use container_of() to retrieve the insn pointer. Another mutex is<br /> used to protect against the current_mode update but not for retrieving<br /> insn_emulation as table-&gt;data is no longer changing.