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authorToshi Kani <toshi.kani@hpe.com>2015-09-24 13:06:04 -0600
committerBorislav Petkov <bp@suse.de>2015-09-25 19:45:59 +0200
commit438470b84c119f4910ebf1fdd26738c8d9881b24 (patch)
tree9ef8e3a17142e34e181a581a04cb3f1b3166815c /drivers/edac/edac_mc_sysfs.c
parent1ea62c59c80090dd4621911e1b7853c379da5fd7 (diff)
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EDAC: Fix sysfs dimm_label store operation
Sysfs "dimm_label" and "chX_dimm_label" nodes have the following issues in their store operation: 1) A newline-terminated input string causes redundant newlines: # echo "test" > /sys/bus/mc0/devices/dimm0/dimm_label # cat /sys/bus/mc0/devices/dimm0/dimm_label test # od -bc /sys/bus/mc0/devices/dimm0/dimm_label 0000000 164 145 163 164 012 012 t e s t \n \n 0000006 2) The original label string (31 characters) cannot be stored due to an improper size check: # echo "CPU_SrcID#0_Ha#0_Chan#0_DIMM#0" > /sys/bus/mc0/devices/dimm0/dimm_label # cat /sys/bus/mc0/devices/dimm0/dimm_label # od -bc /sys/bus/mc0/devices/dimm0/dimm_label 0000000 012 012 \n \n 0000002 3) An input string longer than the buffer size results a wrong label info as it allows a retry with the remaining string: # echo "CPU_SrcID#0_Ha#0_Chan#0_DIMM#0_TEST" > /sys/bus/mc0/devices/dimm0/dimm_label # cat /sys/bus/mc0/devices/dimm0/dimm_label _TEST Fix these issues by making the following changes: 1) Replace a newline character at the end by setting a null. It also assures that the string is null-terminated in the label buffer. 2) Check the label buffer size with 'sizeof(dimm->label)'. 3) Fail a request if its string exceeds the label buffer size. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Robert Elliott <elliott@hpe.com> Link: http://lkml.kernel.org/r/1443121564.25474.160.camel@hpe.com Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'drivers/edac/edac_mc_sysfs.c')
-rw-r--r--drivers/edac/edac_mc_sysfs.c34
1 files changed, 24 insertions, 10 deletions
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index 7d1b31bc6555..bf6b6802105c 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -240,14 +240,21 @@ static ssize_t channel_dimm_label_store(struct device *dev,
struct csrow_info *csrow = to_csrow(dev);
unsigned chan = to_channel(mattr);
struct rank_info *rank = csrow->channels[chan];
+ size_t copy_count = count;
- ssize_t max_size = 0;
+ if (count == 0)
+ return -EINVAL;
+
+ if (data[count - 1] == '\0' || data[count - 1] == '\n')
+ copy_count -= 1;
- max_size = min((ssize_t) count, (ssize_t) EDAC_MC_LABEL_LEN - 1);
- strncpy(rank->dimm->label, data, max_size);
- rank->dimm->label[max_size] = '\0';
+ if (copy_count >= sizeof(rank->dimm->label))
+ return -EINVAL;
- return max_size;
+ strncpy(rank->dimm->label, data, copy_count);
+ rank->dimm->label[copy_count] = '\0';
+
+ return count;
}
/* show function for dynamic chX_ce_count attribute */
@@ -494,14 +501,21 @@ static ssize_t dimmdev_label_store(struct device *dev,
size_t count)
{
struct dimm_info *dimm = to_dimm(dev);
+ size_t copy_count = count;
- ssize_t max_size = 0;
+ if (count == 0)
+ return -EINVAL;
+
+ if (data[count - 1] == '\0' || data[count - 1] == '\n')
+ copy_count -= 1;
- max_size = min((ssize_t) count, (ssize_t) EDAC_MC_LABEL_LEN - 1);
- strncpy(dimm->label, data, max_size);
- dimm->label[max_size] = '\0';
+ if (copy_count >= sizeof(dimm->label))
+ return -EINVAL;
- return max_size;
+ strncpy(dimm->label, data, copy_count);
+ dimm->label[copy_count] = '\0';
+
+ return count;
}
static ssize_t dimmdev_size_show(struct device *dev,