This is a note to let you know that I've just added the patch titled

    gen_stats.c: Duplicate xstats buffer for later use

to the 3.19-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     gen_stats.c-duplicate-xstats-buffer-for-later-use.patch
and it can be found in the queue-3.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From foo@baz Wed Mar 11 11:44:33 CET 2015
From: =?UTF-8?q?Ignacy=20Gaw=C4=99dzki?=
 <[email protected]>
Date: Fri, 13 Feb 2015 14:47:05 -0800
Subject: gen_stats.c: Duplicate xstats buffer for later use
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: =?UTF-8?q?Ignacy=20Gaw=C4=99dzki?=

[ Upstream commit 1c4cff0cf55011792125b6041bc4e9713e46240f ]

The gnet_stats_copy_app() function gets called, more often than not, with its
second argument a pointer to an automatic variable in the caller's stack.
Therefore, to avoid copying garbage afterwards when calling
gnet_stats_finish_copy(), this data is better copied to a dynamically allocated
memory that gets freed after use.

[[email protected]: remove a useless kfree()]

Signed-off-by: Ignacy GawÄ™dzki <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/core/gen_stats.c |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -32,6 +32,9 @@ gnet_stats_copy(struct gnet_dump *d, int
        return 0;
 
 nla_put_failure:
+       kfree(d->xstats);
+       d->xstats = NULL;
+       d->xstats_len = 0;
        spin_unlock_bh(d->lock);
        return -1;
 }
@@ -305,7 +308,9 @@ int
 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 {
        if (d->compat_xstats) {
-               d->xstats = st;
+               d->xstats = kmemdup(st, len, GFP_ATOMIC);
+               if (!d->xstats)
+                       goto err_out;
                d->xstats_len = len;
        }
 
@@ -313,6 +318,11 @@ gnet_stats_copy_app(struct gnet_dump *d,
                return gnet_stats_copy(d, TCA_STATS_APP, st, len);
 
        return 0;
+
+err_out:
+       d->xstats_len = 0;
+       spin_unlock_bh(d->lock);
+       return -1;
 }
 EXPORT_SYMBOL(gnet_stats_copy_app);
 
@@ -345,6 +355,9 @@ gnet_stats_finish_copy(struct gnet_dump
                        return -1;
        }
 
+       kfree(d->xstats);
+       d->xstats = NULL;
+       d->xstats_len = 0;
        spin_unlock_bh(d->lock);
        return 0;
 }


Patches currently in stable-queue which might be from 
[email protected] are

queue-3.19/gen_stats.c-duplicate-xstats-buffer-for-later-use.patch
queue-3.19/ematch-fix-auto-loading-of-ematch-modules.patch
queue-3.19/rtnetlink-call-dellink-on-failure-when-newlink-exists.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to