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authorPaul Meyer <Paul.Meyer@microsoft.com>2017-11-14 23:06:47 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-11-28 18:56:26 +0300
commit297d6b6e56c2977fc504c61bbeeaa21296923f89 (patch)
treef9bb8a9204769647e7341dca0f26d1a6cc77e360
parent7fa32e5ec28b1609abc0b797b58267f725fc3964 (diff)
downloadlinux-297d6b6e56c2977fc504c61bbeeaa21296923f89.tar.xz
hv: kvp: Avoid reading past allocated blocks from KVP file
While reading in more than one block (50) of KVP records, the allocation goes per block, but the reads used the total number of allocated records (without resetting the pointer/stream). This causes the records buffer to overrun when the refresh reads more than one block over the previous capacity (e.g. reading more than 100 KVP records whereas the in-memory database was empty before). Fix this by reading the correct number of KVP records from file each time. Signed-off-by: Paul Meyer <Paul.Meyer@microsoft.com> Signed-off-by: Long Li <longli@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--tools/hv/hv_kvp_daemon.c70
1 files changed, 14 insertions, 56 deletions
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index eaa3bec273c8..4c99c57736ce 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -193,11 +193,14 @@ static void kvp_update_mem_state(int pool)
for (;;) {
readp = &record[records_read];
records_read += fread(readp, sizeof(struct kvp_record),
- ENTRIES_PER_BLOCK * num_blocks,
- filep);
+ ENTRIES_PER_BLOCK * num_blocks - records_read,
+ filep);
if (ferror(filep)) {
- syslog(LOG_ERR, "Failed to read file, pool: %d", pool);
+ syslog(LOG_ERR,
+ "Failed to read file, pool: %d; error: %d %s",
+ pool, errno, strerror(errno));
+ kvp_release_lock(pool);
exit(EXIT_FAILURE);
}
@@ -210,6 +213,7 @@ static void kvp_update_mem_state(int pool)
if (record == NULL) {
syslog(LOG_ERR, "malloc failed");
+ kvp_release_lock(pool);
exit(EXIT_FAILURE);
}
continue;
@@ -224,15 +228,11 @@ static void kvp_update_mem_state(int pool)
fclose(filep);
kvp_release_lock(pool);
}
+
static int kvp_file_init(void)
{
int fd;
- FILE *filep;
- size_t records_read;
char *fname;
- struct kvp_record *record;
- struct kvp_record *readp;
- int num_blocks;
int i;
int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
@@ -246,61 +246,19 @@ static int kvp_file_init(void)
for (i = 0; i < KVP_POOL_COUNT; i++) {
fname = kvp_file_info[i].fname;
- records_read = 0;
- num_blocks = 1;
sprintf(fname, "%s/.kvp_pool_%d", KVP_CONFIG_LOC, i);
fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0644 /* rw-r--r-- */);
if (fd == -1)
return 1;
-
- filep = fopen(fname, "re");
- if (!filep) {
- close(fd);
- return 1;
- }
-
- record = malloc(alloc_unit * num_blocks);
- if (record == NULL) {
- fclose(filep);
- close(fd);
- return 1;
- }
- for (;;) {
- readp = &record[records_read];
- records_read += fread(readp, sizeof(struct kvp_record),
- ENTRIES_PER_BLOCK,
- filep);
-
- if (ferror(filep)) {
- syslog(LOG_ERR, "Failed to read file, pool: %d",
- i);
- exit(EXIT_FAILURE);
- }
-
- if (!feof(filep)) {
- /*
- * We have more data to read.
- */
- num_blocks++;
- record = realloc(record, alloc_unit *
- num_blocks);
- if (record == NULL) {
- fclose(filep);
- close(fd);
- return 1;
- }
- continue;
- }
- break;
- }
kvp_file_info[i].fd = fd;
- kvp_file_info[i].num_blocks = num_blocks;
- kvp_file_info[i].records = record;
- kvp_file_info[i].num_records = records_read;
- fclose(filep);
-
+ kvp_file_info[i].num_blocks = 1;
+ kvp_file_info[i].records = malloc(alloc_unit);
+ if (kvp_file_info[i].records == NULL)
+ return 1;
+ kvp_file_info[i].num_records = 0;
+ kvp_update_mem_state(i);
}
return 0;