Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH] zram: don't copy invalid compression algorithms | Date | Mon, 7 Sep 2015 21:48:30 +0100 |
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Validate the new compression algorithm before copying it into the zram 'compressor' field, keeping the old one if it's invalid.
The error path code is also slightly refactored.
Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/block/zram/zram_drv.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9c01f5bfa33f..33551ec9e7f5 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -367,10 +367,15 @@ static ssize_t comp_algorithm_store(struct device *dev, down_write(&zram->init_lock); if (init_done(zram)) { - up_write(&zram->init_lock); pr_info("Can't change algorithm for initialized device\n"); - return -EBUSY; + len = -EBUSY; + goto out; + } + if (!zcomp_available_algorithm(buf)) { + len = -EINVAL; + goto out; } + strlcpy(zram->compressor, buf, sizeof(zram->compressor)); /* ignore trailing newline */ @@ -378,9 +383,7 @@ static ssize_t comp_algorithm_store(struct device *dev, if (sz > 0 && zram->compressor[sz - 1] == '\n') zram->compressor[sz - 1] = 0x00; - if (!zcomp_available_algorithm(zram->compressor)) - len = -EINVAL; - +out: up_write(&zram->init_lock); return len; }
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