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| author | Toshi Kani <toshi.kani@hpe.com> | 2015-09-24 22:06:04 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2015-09-25 20:45:59 +0300 |
| commit | 438470b84c119f4910ebf1fdd26738c8d9881b24 (patch) | |
| tree | 9ef8e3a17142e34e181a581a04cb3f1b3166815c /drivers/edac | |
| parent | 1ea62c59c80090dd4621911e1b7853c379da5fd7 (diff) | |
| download | linux-438470b84c119f4910ebf1fdd26738c8d9881b24.tar.xz | |
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')
| -rw-r--r-- | drivers/edac/edac_mc_sysfs.c | 34 |
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, |