CVE-2023-52791

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> i2c: core: Run atomic i2c xfer when !preemptible<br /> <br /> Since bae1d3a05a8b, i2c transfers are non-atomic if preemption is<br /> disabled. However, non-atomic i2c transfers require preemption (e.g. in<br /> wait_for_completion() while waiting for the DMA).<br /> <br /> panic() calls preempt_disable_notrace() before calling<br /> emergency_restart(). Therefore, if an i2c device is used for the<br /> restart, the xfer should be atomic. This avoids warnings like:<br /> <br /> [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0<br /> [ 12.676926] Voluntary context switch within RCU read-side critical section!<br /> ...<br /> [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114<br /> [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70<br /> ...<br /> [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58<br /> [ 13.001050] machine_restart from panic+0x2a8/0x32c<br /> <br /> Use !preemptible() instead, which is basically the same check as<br /> pre-v5.2.