5.4-stable patches

added patches:
	memcg-charge-fs_context-and-legacy_fs_context.patch

diff --git a/queue-5.4/memcg-charge-fs_context-and-legacy_fs_context.patch b/queue-5.4/memcg-charge-fs_context-and-legacy_fs_context.patch
new file mode 100644 (file)
index 0000000..5d3086d
--- /dev/null
+++ b/queue-5.4/memcg-charge-fs_context-and-legacy_fs_context.patch
@@ -0,0 +1,107 @@
+From bb902cb47cf93b33cd92b3b7a4019330a03ef57f Mon Sep 17 00:00:00 2001
+From: Yutian Yang <nglaive@gmail.com>
+Date: Thu, 2 Sep 2021 14:55:07 -0700
+Subject: memcg: charge fs_context and legacy_fs_context
+
+From: Yutian Yang <nglaive@gmail.com>
+
+commit bb902cb47cf93b33cd92b3b7a4019330a03ef57f upstream.
+
+This patch adds accounting flags to fs_context and legacy_fs_context
+allocation sites so that kernel could correctly charge these objects.
+
+We have written a PoC to demonstrate the effect of the missing-charging
+bugs.  The PoC takes around 1,200MB unaccounted memory, while it is
+charged for only 362MB memory usage.  We evaluate the PoC on QEMU x86_64
+v5.2.90 + Linux kernel v5.10.19 + Debian buster.  All the limitations
+including ulimits and sysctl variables are set as default.  Specifically,
+the hard NOFILE limit and nr_open in sysctl are both 1,048,576.
+
+/*------------------------- POC code ----------------------------*/
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/file.h>
+#include <time.h>
+#include <sys/wait.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <linux/mount.h>
+
+#define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE); \
+                        } while (0)
+
+#define STACK_SIZE (8 * 1024)
+#ifndef __NR_fsopen
+#define __NR_fsopen 430
+#endif
+static inline int fsopen(const char *fs_name, unsigned int flags)
+{
+        return syscall(__NR_fsopen, fs_name, flags);
+}
+
+static char thread_stack[512][STACK_SIZE];
+
+int thread_fn(void* arg)
+{
+  for (int i = 0; i< 800000; ++i) {
+    int fsfd = fsopen("nfs", FSOPEN_CLOEXEC);
+    if (fsfd == -1) {
+      errExit("fsopen");
+    }
+  }
+  while(1);
+  return 0;
+}
+
+int main(int argc, char *argv[]) {
+  int thread_pid;
+  for (int i = 0; i < 1; ++i) {
+    thread_pid = clone(thread_fn, thread_stack[i] + STACK_SIZE, \
+      SIGCHLD, NULL);
+  }
+  while(1);
+  return 0;
+}
+
+/*-------------------------- end --------------------------------*/
+
+Link: https://lkml.kernel.org/r/1626517201-24086-1-git-send-email-nglaive@gmail.com
+Signed-off-by: Yutian Yang <nglaive@gmail.com>
+Reviewed-by: Shakeel Butt <shakeelb@google.com>
+Cc: Michal Hocko <mhocko@kernel.org>
+Cc: Johannes Weiner <hannes@cmpxchg.org>
+Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
+Cc: <shenwenbo@zju.edu.cn>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/fs_context.c |    4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/fs/fs_context.c
++++ b/fs/fs_context.c
+@@ -258,7 +258,7 @@ static struct fs_context *alloc_fs_conte
+       struct fs_context *fc;
+       int ret = -ENOMEM;
+ 
+-      fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
++      fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL_ACCOUNT);
+       if (!fc)
+               return ERR_PTR(-ENOMEM);
+ 
+@@ -686,7 +686,7 @@ const struct fs_context_operations legac
+  */
+ static int legacy_init_fs_context(struct fs_context *fc)
+ {
+-      fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL);
++      fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL_ACCOUNT);
+       if (!fc->fs_private)
+               return -ENOMEM;
+       fc->ops = &legacy_fs_context_ops;

diff --git a/queue-5.4/series b/queue-5.4/series
index f3f36965a2f8b1fe52b2d911639fd12031473d25..99ca66b23639c1657560ede0d020ffe54c45da42 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -12,3 +12,4 @@ drm-nouveau-fix-off-by-one-in-bios-boundary-checking.patch
 mm-kmemleak-avoid-scanning-potential-huge-holes.patch
 block-bio-integrity-advance-seed-correctly-for-larger-interval-sizes.patch
 revert-asoc-mediatek-check-for-error-clk-pointer.patch
+memcg-charge-fs_context-and-legacy_fs_context.patch