From 118f31b4964fa9fce65b0901ef598c734553cfc7 Mon Sep 17 00:00:00 2001 From: Thore Sommer Date: Tue, 25 Jan 2022 15:05:47 +0100 Subject: [PATCH] dm ima: fix wrong length calculation for no_data string All entries measured by dm ima are prefixed by a version string (dm_version=N.N.N). When there is no data to measure, the entire buffer is overwritten with a string containing the version string again and the length of that string is added to the length of the version string. The new length is now wrong because it contains the version string twice. This caused entries like this: dm_version=4.45.0;name=test,uuid=test;table_clear=no_data; \ \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 \ current_device_capacity=204808; Signed-off-by: Thore Sommer Signed-off-by: Mike Snitzer --- drivers/md/dm-ima.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c index 9579999..1842d3a 100644 --- a/drivers/md/dm-ima.c +++ b/drivers/md/dm-ima.c @@ -455,7 +455,7 @@ void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap) scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, "%sname=%s,uuid=%s;device_resume=no_data;", DM_IMA_VERSION_STR, dev_name, dev_uuid); - l += strlen(device_table_data); + l = strlen(device_table_data); } @@ -568,7 +568,7 @@ void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all) scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, "%sname=%s,uuid=%s;device_remove=no_data;", DM_IMA_VERSION_STR, dev_name, dev_uuid); - l += strlen(device_table_data); + l = strlen(device_table_data); } memcpy(device_table_data + l, remove_all_str, remove_all_len); @@ -654,7 +654,7 @@ void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map) scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, "%sname=%s,uuid=%s;table_clear=no_data;", DM_IMA_VERSION_STR, dev_name, dev_uuid); - l += strlen(device_table_data); + l = strlen(device_table_data); } capacity_len = strlen(capacity_str); -- 2.7.4