From: Masami Hiramatsu <mhiramat(a)kernel.org>
Enable the notrace function check on the architecture which doesn't
support kprobes on ftrace but support dynamic ftrace. This notrace
function check is not only for the kprobes on ftrace but also
sw-breakpoint based kprobes.
Thus there is no reason to limit this check for the arch which
supports kprobes on ftrace.
This also changes the dependency of Kconfig. Because kprobe event
uses the function tracer's address list for identifying notrace
function, if the CONFIG_DYNAMIC_FTRACE=n, it can not check whether
the target function is notrace or not.
Link: https://lkml.kernel.org/r/20210105065730.2634785-1-naveen.n.rao@linux.vnet.…
Link: https://lkml.kernel.org/r/161007957862.114704.4512260007555399463.stgit@dev…
Cc: stable(a)vger.kernel.org
Fixes: 45408c4f92506 ("tracing: kprobes: Prohibit probing on notrace function")
Acked-by: Naveen N. Rao <naveen.n.rao(a)linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
kernel/trace/Kconfig | 2 +-
kernel/trace/trace_kprobe.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index d5a19413d4f8..c1a62ae7e812 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -538,7 +538,7 @@ config KPROBE_EVENTS
config KPROBE_EVENTS_ON_NOTRACE
bool "Do NOT protect notrace function from kprobe events"
depends on KPROBE_EVENTS
- depends on KPROBES_ON_FTRACE
+ depends on DYNAMIC_FTRACE
default n
help
This is only for the developers who want to debug ftrace itself
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9c31f42245e9..e6fba1798771 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -434,7 +434,7 @@ static int disable_trace_kprobe(struct trace_event_call *call,
return 0;
}
-#if defined(CONFIG_KPROBES_ON_FTRACE) && \
+#if defined(CONFIG_DYNAMIC_FTRACE) && \
!defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
static bool __within_notrace_func(unsigned long addr)
{
--
2.30.0.windows.1
From: Johannes Berg <johannes.berg(a)intel.com>
If userspace tries to change the stub, we need to kill it,
because otherwise it can escape the virtual machine. In a
few cases the stub checks weren't good, e.g. if userspace
just tries to
mmap(0x100000 - 0x1000, 0x3000, ...)
it could succeed to get a new private/anonymous mapping
replacing the stubs. Fix this by checking everywhere, and
checking for _overlap_, not just direct changes.
Cc: stable(a)vger.kernel.org
Fixes: 3963333fe676 ("uml: cover stubs with a VMA")
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
---
arch/um/kernel/tlb.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 61776790cd67..89468da6bf88 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -125,6 +125,9 @@ static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
struct host_vm_op *last;
int fd = -1, ret = 0;
+ if (virt + len > STUB_START && virt < STUB_END)
+ return -EINVAL;
+
if (hvc->userspace)
fd = phys_mapping(phys, &offset);
else
@@ -162,7 +165,7 @@ static int add_munmap(unsigned long addr, unsigned long len,
struct host_vm_op *last;
int ret = 0;
- if ((addr >= STUB_START) && (addr < STUB_END))
+ if (addr + len > STUB_START && addr < STUB_END)
return -EINVAL;
if (hvc->index != 0) {
@@ -192,6 +195,9 @@ static int add_mprotect(unsigned long addr, unsigned long len,
struct host_vm_op *last;
int ret = 0;
+ if (addr + len > STUB_START && addr < STUB_END)
+ return -EINVAL;
+
if (hvc->index != 0) {
last = &hvc->ops[hvc->index - 1];
if ((last->type == MPROTECT) &&
@@ -472,6 +478,10 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
struct mm_id *mm_id;
address &= PAGE_MASK;
+
+ if (address >= STUB_START && address < STUB_END)
+ goto kill;
+
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
goto kill;
--
2.26.2