averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-07-25 16:19:48 +02:00
Code Issues Packages Projects Releases Wiki Activity

riscv: stacktrace: Disable KASAN checks for non-current tasks

Browse Source 
Unwinding the stack of a task other than current, KASAN would report
"BUG: KASAN: out-of-bounds in walk_stackframe+0x41c/0x460"

There is a same issue on x86 and has been resolved by the commit
84936118bd ("x86/unwind: Disable KASAN checks for non-current tasks")
The solution could be applied to RISC-V too.

This patch also can solve the issue:
https://seclists.org/oss-sec/2025/q4/23

Fixes: 5d8544e2d0 ("RISC-V: Generic library routines and assembly")
Co-developed-by: Jiakai Xu <xujiakai2025@iscas.ac.cn>
Signed-off-by: Jiakai Xu <xujiakai2025@iscas.ac.cn>
Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn>
Link: https://lore.kernel.org/r/20251022072608.743484-1-zhangchunyan@iscas.ac.cn
[pjw@kernel.org: clean up checkpatch issues]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
This commit is contained in:
Chunyan Zhang
2025-10-27 11:40:43 -06:00
committed by Paul Walmsley
parent dcb6fa37fd
commit 060ea84a48
1 changed files with 19 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/riscv/kernel/stacktrace.c
+19 -2
View File
@@ -16,6 +16,22 @@
#ifdef CONFIG_FRAME_POINTER
/*
* This disables KASAN checking when reading a value from another task's stack,
* since the other task could be running on another CPU and could have poisoned
* the stack in the meantime.
*/
#define READ_ONCE_TASK_STACK(task, x) \
({ \
unsigned long val; \
unsigned long addr = x; \
if ((task) == current) \
val = READ_ONCE(addr); \
else \
val = READ_ONCE_NOCHECK(addr); \
val; \
})
extern asmlinkage void handle_exception(void);
extern unsigned long ret_from_exception_end;
@@ -69,8 +85,9 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
fp = frame->ra;
pc = regs->ra;
} else {
fp = frame->fp;
pc = ftrace_graph_ret_addr(current, &graph_idx, frame->ra,
fp = READ_ONCE_TASK_STACK(task, frame->fp);
pc = READ_ONCE_TASK_STACK(task, frame->ra);
pc = ftrace_graph_ret_addr(current, &graph_idx, pc,
&frame->ra);
if (pc >= (unsigned long)handle_exception &&
pc < (unsigned long)&ret_from_exception_end) {