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hv: kvp: Avoid reading past allocated blocks from KVP file 

commit 297d6b6e56 upstream.

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>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Paul Meyer 2017-11-14 13:06:47 -07:00 committed by Greg Kroah-Hartman
parent 3f77a2c68b
commit 070703364a
1 changed files with 14 additions and 56 deletions
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70
tools/hv/hv_kvp_daemon.c
View File

@ -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;