CVE-2024-57939 Information

Description

In the Linux kernel the following vulnerability has been resolved:

riscv: Fix sleeping in invalid context in die()

die() can be called in exception handler and therefore cannot sleep. However die() takes spinlock_t which can sleep with PREEMPT_RT enabled. That causes the following warning:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1 irqs_disabled(): 1 non_block: 0 pid: 285 name: mutex preempt_count: 110001 expected: 0 RCU nest depth: 0 expected: 0 CPU: 0 UID: 0 PID: 285 Comm: mutex Not tainted 6.12.0-rc7-00022-ge19049cf7d56-dirty 234 Hardware name: riscv-virtioqemu (DT) Call Trace: dump_backtrace+0x1c/0x24 show_stack+0x2c/0x38 dump_stack_lvl+0x5a/0x72 dump_stack+0x14/0x1c __might_resched+0x130/0x13a rt_spin_lock+0x2a/0x5c die+0x24/0x112 do_trap_insn_illegal+0xa0/0xea _new_vmalloc_restore_context_a0+0xcc/0xd8 Oops - illegal instruction [1]

Switch to use raw_spinlock_t which does not sleep even with PREEMPT_RT enabled.

Reference

https://git.kernel.org/stable/c/6a97f4118ac07cfdc316433f385dbdc12af5025e https://git.kernel.org/stable/c/76ab0afcdbe8c9685b589016ee1c0e25fe596707 https://git.kernel.org/stable/c/c21df31fc2a4afc02a6e56511364e9e793ea92ec https://git.kernel.org/stable/c/f48f060a4b36b5e96628f6c3fb1540f1e8dedb69