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: NToshi Kani <toshi.kani@hpe.com> Acked-by: NTony 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.comSigned-off-by: NBorislav Petkov <bp@suse.de>
Showing
想要评论请 注册 或 登录