From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57944 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727944AbeHXAmA (ORCPT ); Thu, 23 Aug 2018 20:42:00 -0400 Date: Thu, 23 Aug 2018 14:10:28 -0700 From: akpm@linux-foundation.org To: minchan@kernel.org, mm-commits@vger.kernel.org, peskal@google.com, sergey.senozhatsky@gmail.com, stable@vger.kernel.org Subject: [merged] zram-fix-bug-storing-backing_dev.patch removed from -mm tree Message-ID: <20180823211028.YTPVsgNAD%akpm@linux-foundation.org> Sender: stable-owner@vger.kernel.org List-ID: The patch titled Subject: drivers/block/zram/zram_drv.c: fix bug storing backing_dev has been removed from the -mm tree. Its filename was zram-fix-bug-storing-backing_dev.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Peter Kalauskas Subject: drivers/block/zram/zram_drv.c: fix bug storing backing_dev The call to strlcpy in backing_dev_store is incorrect. It should take the size of the destination buffer instead of the size of the source buffer. Additionally, ignore the newline character (\n) when reading the new file_name buffer. This makes it possible to set the backing_dev as follows: echo /dev/sdX > /sys/block/zram0/backing_dev The reason it worked before was the fact that strlcpy() copies 'len - 1' bytes, which is strlen(buf) - 1 in our case, so it accidentally didn't copy the trailing new line symbol. Which also means that "echo -n /dev/sdX" most likely was broken. Signed-off-by: Peter Kalauskas Link: http://lkml.kernel.org/r/20180813061623.GC64836@rodete-desktop-imager.corp.google.com Acked-by: Minchan Kim Reviewed-by: Sergey Senozhatsky Cc: [4.14+] Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/block/zram/zram_drv.c~zram-fix-bug-storing-backing_dev +++ a/drivers/block/zram/zram_drv.c @@ -337,6 +337,7 @@ static ssize_t backing_dev_store(struct struct device_attribute *attr, const char *buf, size_t len) { char *file_name; + size_t sz; struct file *backing_dev = NULL; struct inode *inode; struct address_space *mapping; @@ -357,7 +358,11 @@ static ssize_t backing_dev_store(struct goto out; } - strlcpy(file_name, buf, len); + strlcpy(file_name, buf, PATH_MAX); + /* ignore trailing newline */ + sz = strlen(file_name); + if (sz > 0 && file_name[sz - 1] == '\n') + file_name[sz - 1] = 0x00; backing_dev = filp_open(file_name, O_RDWR|O_LARGEFILE, 0); if (IS_ERR(backing_dev)) { _ Patches currently in -mm which might be from peskal@google.com are