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| author | Vladimir Zapolskiy <vz@mleia.com> | 2015-05-22 00:21:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-01 10:17:17 +0900 |
| commit | eaa5cd926345f86e9df1eb6b0490da539f5ce7d0 (patch) | |
| tree | a1048947c68ae9bae7c93a3848387fcd557b5839 /fs/sysfs/file.c | |
| parent | 9ba8af66432cb8e82553f2e273eb11db0cec7d2d (diff) | |
| download | lwn-eaa5cd926345f86e9df1eb6b0490da539f5ce7d0.tar.gz lwn-eaa5cd926345f86e9df1eb6b0490da539f5ce7d0.zip | |
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>
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 7c2867b44141..6c95628ea377 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -90,7 +90,7 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, return 0; if (size) { - if (pos > size) + if (pos >= size) return 0; if (pos + count > size) count = size - pos; |