4.4-stable patches

added patches:
	ftrace-do-not-blindly-read-the-ip-address-in-ftrace_bug.patch

diff --git a/queue-4.4/ftrace-do-not-blindly-read-the-ip-address-in-ftrace_bug.patch b/queue-4.4/ftrace-do-not-blindly-read-the-ip-address-in-ftrace_bug.patch
new file mode 100644 (file)
index 0000000..f52cf3c
--- /dev/null
+++ b/queue-4.4/ftrace-do-not-blindly-read-the-ip-address-in-ftrace_bug.patch
@@ -0,0 +1,55 @@
+From 6c14133d2d3f768e0a35128faac8aa6ed4815051 Mon Sep 17 00:00:00 2001
+From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
+Date: Mon, 7 Jun 2021 21:39:08 -0400
+Subject: ftrace: Do not blindly read the ip address in ftrace_bug()
+
+From: Steven Rostedt (VMware) <rostedt@goodmis.org>
+
+commit 6c14133d2d3f768e0a35128faac8aa6ed4815051 upstream.
+
+It was reported that a bug on arm64 caused a bad ip address to be used for
+updating into a nop in ftrace_init(), but the error path (rightfully)
+returned -EINVAL and not -EFAULT, as the bug caused more than one error to
+occur. But because -EINVAL was returned, the ftrace_bug() tried to report
+what was at the location of the ip address, and read it directly. This
+caused the machine to panic, as the ip was not pointing to a valid memory
+address.
+
+Instead, read the ip address with copy_from_kernel_nofault() to safely
+access the memory, and if it faults, report that the address faulted,
+otherwise report what was in that location.
+
+Link: https://lore.kernel.org/lkml/20210607032329.28671-1-mark-pk.tsai@mediatek.com/
+
+Cc: stable@vger.kernel.org
+Fixes: 05736a427f7e1 ("ftrace: warn on failure to disable mcount callers")
+Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
+Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
+Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/trace/ftrace.c |    8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+--- a/kernel/trace/ftrace.c
++++ b/kernel/trace/ftrace.c
+@@ -1943,12 +1943,18 @@ static int ftrace_hash_ipmodify_update(s
+ 
+ static void print_ip_ins(const char *fmt, unsigned char *p)
+ {
++      char ins[MCOUNT_INSN_SIZE];
+       int i;
+ 
++      if (probe_kernel_read(ins, p, MCOUNT_INSN_SIZE)) {
++              printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
++              return;
++      }
++
+       printk(KERN_CONT "%s", fmt);
+ 
+       for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+-              printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
++              printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]);
+ }
+ 
+ static struct ftrace_ops *

diff --git a/queue-4.4/series b/queue-4.4/series
index 6d7dfb061d2390d14365cbcbcdaf8f2c2ac42832..5cbcf528819985258b83855ec954947803b75e76 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -31,3 +31,4 @@ perf-session-correct-buffer-copying-when-peeking-eve.patch
 kvm-fix-previous-commit-for-32-bit-builds.patch
 nfsv4-nfs4_proc_set_acl-needs-to-restore-nfs_cap_uidgid_nomap-on-error.patch
 scsi-core-only-put-parent-device-if-host-state-differs-from-shost_created.patch
+ftrace-do-not-blindly-read-the-ip-address-in-ftrace_bug.patch