Bug 2405778 (CVE-2023-53694) - CVE-2023-53694 kernel: riscv: ftrace: Fixup panic by disabling preemption
Summary: CVE-2023-53694 kernel: riscv: ftrace: Fixup panic by disabling preemption
Keywords:
Status: NEW
Alias: CVE-2023-53694
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-10-22 14:06 UTC by OSIDB Bzimport
Modified: 2025-10-24 18:09 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2025-10-22 14:06:39 UTC
In the Linux kernel, the following vulnerability has been resolved:

riscv: ftrace: Fixup panic by disabling preemption

In RISCV, we must use an AUIPC + JALR pair to encode an immediate,
forming a jump that jumps to an address over 4K. This may cause errors
if we want to enable kernel preemption and remove dependency from
patching code with stop_machine(). For example, if a task was switched
out on auipc. And, if we changed the ftrace function before it was
switched back, then it would jump to an address that has updated 11:0
bits mixing with previous XLEN:12 part.

p: patched area performed by dynamic ftrace
ftrace_prologue:
p|      REG_S   ra, -SZREG(sp)
p|      auipc   ra, 0x? ------------> preempted
					...
				change ftrace function
					...
p|      jalr    -?(ra) <------------- switched back
p|      REG_L   ra, -SZREG(sp)
func:
	xxx
	ret


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