From: Sasha Levin <sashal@kernel.org>
Date: Sat, 6 Feb 2021 15:02:51 +0000 (-0500)
Subject: Fixes for 4.4
X-Git-Tag: v4.14.220~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=12acea847eacd8c9048a57de8886dc3ea4184513;p=thirdparty%2Fkernel%2Fstable-queue.git

Fixes for 4.4

Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/queue-4.4/series b/queue-4.4/series
index eda79455b5c..ebf754b7f68 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -12,3 +12,4 @@ futex-handle-faults-correctly-for-pi-futexes.patch
 usb-udc-core-use-lock-when-write-to-soft_connect.patch
 scsi-libfc-avoid-invoking-response-handler-twice-if-.patch
 scsi-ibmvfc-set-default-timeout-to-avoid-crash-durin.patch
+stable-clamp-sublevel-in-4.4-and-4.9.patch
diff --git a/queue-4.4/stable-clamp-sublevel-in-4.4-and-4.9.patch b/queue-4.4/stable-clamp-sublevel-in-4.4-and-4.9.patch
new file mode 100644
index 00000000000..7d05eb0fb72
--- /dev/null
+++ b/queue-4.4/stable-clamp-sublevel-in-4.4-and-4.9.patch
@@ -0,0 +1,46 @@
+From 832af6cd3e1757ef05e1fc2a17cd65a5254dd8ce Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Fri, 5 Feb 2021 12:47:02 -0500
+Subject: stable: clamp SUBLEVEL in 4.4 and 4.9
+
+Right now SUBLEVEL is overflowing, and some userspace may start treating
+4.9.256 as 4.10. While out of tree modules have different ways of
+  extracting the version number (and we're generally ok with breaking
+them), we do care about breaking userspace and it would appear that this
+overflow might do just that.
+
+Our rules around userspace ABI in the stable kernel are pretty simple:
+we don't break it. Thus, while userspace may be checking major/minor, it
+shouldn't be doing anything with sublevel.
+
+This patch applies a big band-aid to the 4.9 and 4.4 kernels in the form
+of clamping their sublevel to 255.
+
+The clamp is done for the purpose of LINUX_VERSION_CODE only, and
+extracting the version number from the Makefile or "make kernelversion"
+will continue to work as intended.
+
+We might need to do it later in newer trees, but maybe we'll have a
+better solution by then, so I'm ignoring that problem for now.
+
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makefile b/Makefile
+index 0057587d2cbe2..e4c6b6e62edb9 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1068,7 +1068,7 @@ endef
+ 
+ define filechk_version.h
+ 	(echo \#define LINUX_VERSION_CODE $(shell                         \
+-	expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
++	expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 255); \
+ 	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
+ endef
+ 
+-- 
+2.27.0
+