5.4-stable patches

added patches:
	ftrace-use-preempt_enable-disable-notrace-macros-to-avoid-double-fault.patch

diff --git a/queue-5.4/ftrace-use-preempt_enable-disable-notrace-macros-to-avoid-double-fault.patch b/queue-5.4/ftrace-use-preempt_enable-disable-notrace-macros-to-avoid-double-fault.patch
new file mode 100644 (file)
index 0000000..1820ac0
--- /dev/null
+++ b/queue-5.4/ftrace-use-preempt_enable-disable-notrace-macros-to-avoid-double-fault.patch
@@ -0,0 +1,54 @@
+From koichiro.den@canonical.com  Thu Jan  9 11:03:49 2025
+From: Koichiro Den <koichiro.den@canonical.com>
+Date: Wed,  8 Jan 2025 12:17:36 +0900
+Subject: ftrace: use preempt_enable/disable notrace macros to avoid double fault
+To: gregkh@linuxfoundation.org, stable@vger.kernel.org
+Cc: rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, mathieu.desnoyers@efficios.com, zhengyejian1@huawei.com, hagarhem@amazon.com, linux-kernel@vger.kernel.org
+Message-ID: <20250108031736.3318120-1-koichiro.den@canonical.com>
+
+From: Koichiro Den <koichiro.den@canonical.com>
+
+Since the backport commit eea46baf1451 ("ftrace: Fix possible
+use-after-free issue in ftrace_location()") on linux-5.4.y branch, the
+old ftrace_int3_handler()->ftrace_location() path has included
+rcu_read_lock(), which has mcount location inside and leads to potential
+double fault.
+
+Replace rcu_read_lock/unlock with preempt_enable/disable notrace macros
+so that the mcount location does not appear on the int3 handler path.
+
+This fix is specific to linux-5.4.y branch, the only branch still using
+ftrace_int3_handler with commit e60b613df8b6 ("ftrace: Fix possible
+use-after-free issue in ftrace_location()") backported. It also avoids
+the need to backport the code conversion to text_poke() on this branch.
+
+Reported-by: Koichiro Den <koichiro.den@canonical.com>
+Closes: https://lore.kernel.org/all/74gjhwxupvozwop7ndhrh7t5qeckomt7yqvkkbm5j2tlx6dkfk@rgv7sijvry2k
+Fixes: eea46baf1451 ("ftrace: Fix possible use-after-free issue in ftrace_location()") # linux-5.4.y
+Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
+Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/trace/ftrace.c |    4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/kernel/trace/ftrace.c
++++ b/kernel/trace/ftrace.c
+@@ -1554,7 +1554,7 @@ unsigned long ftrace_location_range(unsi
+       struct dyn_ftrace key;
+       unsigned long ip = 0;
+ 
+-      rcu_read_lock();
++      preempt_disable_notrace();
+       key.ip = start;
+       key.flags = end;        /* overload flags, as it is unsigned long */
+ 
+@@ -1572,7 +1572,7 @@ unsigned long ftrace_location_range(unsi
+                       break;
+               }
+       }
+-      rcu_read_unlock();
++      preempt_enable_notrace();
+       return ip;
+ }
+ 

diff --git a/queue-5.4/series b/queue-5.4/series
index 02200d2f1cbb352c7f070d6c2fa733dadff1f4c9..7ee538448cbbffad9444d1dd3b79e003f57db5c9 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -91,3 +91,4 @@ sky2-add-device-id-11ab-4373-for-marvell-88e8075.patch
 net-sctp-prevent-autoclose-integer-overflow-in-sctp_association_init.patch
 drm-adv7511-drop-dsi-single-lane-support.patch
 mm-vmscan-account-for-free-pages-to-prevent-infinite-loop-in-throttle_direct_reclaim.patch
+ftrace-use-preempt_enable-disable-notrace-macros-to-avoid-double-fault.patch