Forgot the fixes line.
* Liam Howlett <liam.howlett@xxxxxxxxxx> [210407 16:00]:
When the superuser flushes the entire cache, the mmap_read_lock() is not
taken, but mmap_read_unlock() is called. Add the missing
mmap_read_lock() call.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
arch/m68k/kernel/sys_m68k.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 1c235d8f53f3..f55bdcb8e4f1 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -388,6 +388,8 @@ sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto out;
+
+ mmap_read_lock(current->mm);
} else {
struct vm_area_struct *vma;
--
2.30.0
From aeee71b15f54426f02f41a4408afbd0b5acab7ec Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Date: Wed, 7 Apr 2021 11:39:06 -0400
Subject: [PATCH] arch/m68k/kernel/sys_m68k: Add missing mmap_read_lock() to
sys_cacheflush()
When the superuser flushes the entire cache, the mmap_read_lock() is not
taken, but mmap_read_unlock() is called. Add the missing
mmap_read_lock() call.
Fixes: cd2567b6850b (m68k: call find_vma with the mmap_sem held in
sys_cacheflush())
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
arch/m68k/kernel/sys_m68k.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 1c235d8f53f3..f55bdcb8e4f1 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -388,6 +388,8 @@ sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto out;
+
+ mmap_read_lock(current->mm);
} else {
struct vm_area_struct *vma;
--
2.30.0
