On Wed, Feb 16, 2022 at 02:13:19PM +0100, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>
The __range_not_ok() helper is an x86 (and sparc64) specific interface
that does roughly the same thing as __access_ok(), but with different
calling conventions.
Change this to use the normal interface in order for consistency as we
clean up all access_ok() implementations.
This changes the limit from TASK_SIZE to TASK_SIZE_MAX, which Al points
out is the right thing do do here anyway.
The callers have to use __access_ok() instead of the normal access_ok()
though, because on x86 that contains a WARN_ON_IN_IRQ() check that cannot
be used inside of NMI context while tracing.
Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@xxxxxxxxxxxxxxxxxxxxx/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/x86/events/core.c | 2 +-
arch/x86/include/asm/uaccess.h | 10 ++++++----
arch/x86/kernel/dumpstack.c | 2 +-
arch/x86/kernel/stacktrace.c | 2 +-
arch/x86/lib/usercopy.c | 2 +-
5 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index e686c5e0537b..eef816fc216d 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2794,7 +2794,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
static inline int
valid_user_frame(const void __user *fp, unsigned long size)
{
- return (__range_not_ok(fp, size, TASK_SIZE) == 0);
+ return __access_ok(fp, size);
}
valid_user_frame just need to go away and the following __get_user calls
replaced with normal get_user ones.
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 53de044e5654..da534fb7b5c6 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -85,7 +85,7 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src,
* Make sure userspace isn't trying to trick us into dumping kernel
* memory by pointing the userspace instruction pointer at it.
*/
- if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX))
+ if (!__access_ok((void __user *)src, nbytes))
return -EINVAL;
This one is not needed at all as copy_from_user_nmi already checks the
access range.
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 15b058eefc4e..ee117fcf46ed 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -90,7 +90,7 @@ copy_stack_frame(const struct stack_frame_user __user *fp,
{
int ret;
- if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE))
+ if (!__access_ok(fp, sizeof(*frame)))
return 0;
Just switch the __get_user calls below to get_user instead.
