From: Vladimir Zapolskiy <vz@mleia.com>
Date: Thu, 21 May 2015 21:21:16 +0000 (+0300)
Subject: fs: sysfs: don't pass count == 0 to bin file readers
X-Git-Tag: omap-for-v4.2/fixes-rc1^2~93^2~6
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eaa5cd926345f86e9df1eb6b0490da539f5ce7d0;p=pandora-kernel.git

fs: sysfs: don't pass count == 0 to bin file readers

If count == 0 bytes are requested by a reader, sysfs_kf_bin_read()
deliberately returns 0 without passing a potentially harmful value to
some externally defined underlying battr->read() function.

However in case of (pos == size && count) the next clause always sets
count to 0 and this value is handed over to battr->read().

The change intends to make obsolete (and remove later) a redundant
sanity check in battr->read(), if it is present, or add more
protection to struct bin_attribute users, who does not care about
input arguments.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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