Handle null pkgcache for local/sync db_populate()
 

In sync_db_populate() and local_db_populate(), a NULL
db->pkgcache is not caught, allowing the functions to continue
instead of exiting.

A later alpm_list_msort() call which uses alpm_list_nth()
will thus traverse invalid pointers in a non-existent
db->pkgcache->list.

pmerrno is set to PM_ERR_MEMORY as _alpm_pkghash_create() will
only return NULL when we run out of memory / exceed max hash
table size. The local/sync db_populate() functions are also
exited.

db->pkgcache_loaded is initialized to 0 in _alpm_db_new() as
this value is used to ascertain the whether db->pkgcache is
loaded.

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
---
lib/libalpm/be_local.c | 4 ++++
lib/libalpm/be_sync.c | 8 +++++++-
lib/libalpm/db.c | 1 +
3 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index c5b2498..5858270 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -393,6 +393,10 @@ static int local_db_populate(pmdb_t *db)

/* initialize hash at 50% full */
db->pkgcache = _alpm_pkghash_create(est_count * 2);
+ if(db->pkgcache == NULL){
+ closedir(dbdir);
+ RET_ERR(PM_ERR_MEMORY, -1);
+ }

while((ent = readdir(dbdir)) != NULL) {
const char *name = ent->d_name;
diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 4ad045c..4e9b4d3 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -234,6 +234,9 @@ static int sync_db_populate(pmdb_t *db)

/* initialize hash at 66% full */
db->pkgcache = _alpm_pkghash_create(est_count * 3 / 2);
+ if(db->pkgcache == NULL) {
+ RET_ERR(PM_ERR_MEMORY, -1);
+ }

while(archive_read_next_header(archive, &entry) == ARCHIVE_OK) {
const struct stat *st;
@@ -348,6 +351,9 @@ static int sync_db_read(pmdb_t *db, struct archive *archive,
if(likely_pkg && strcmp(likely_pkg->name, pkgname) == 0) {
pkg = likely_pkg;
} else {
+ if(db->pkgcache == NULL) {
+ RET_ERR(PM_ERR_MEMORY, -1);
+ }
pkg = _alpm_pkghash_find(db->pkgcache, pkgname);
}
if(pkg == NULL) {
@@ -459,10 +465,10 @@ pmdb_t *_alpm_db_register_sync(const char *treename)
_alpm_log(PM_LOG_DEBUG, "registering sync database '%s'
", treename);

db = _alpm_db_new(treename, 0);
- db->ops = &sync_db_ops;
if(db == NULL) {
RET_ERR(PM_ERR_DB_CREATE, NULL);
}
+ db->ops = &sync_db_ops;

handle->dbs_sync = alpm_list_add(handle->dbs_sync, db);
return(db);
diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 02f8282..d43a16b 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -370,6 +370,7 @@ pmdb_t *_alpm_db_new(const char *treename, int is_local)
CALLOC(db, 1, sizeof(pmdb_t), RET_ERR(PM_ERR_MEMORY, NULL));
STRDUP(db->treename, treename, RET_ERR(PM_ERR_MEMORY, NULL));
db->is_local = is_local;
+ db->pkgcache_loaded = 0;

return(db);
}
--
1.7.4

Handle null pkgcache for local/sync db_populate()
 

On Mon, Feb 7, 2011 at 4:59 PM, Pang Yan Han <pangyanhan@gmail.com> wrote:
> In sync_db_populate() and local_db_populate(), a NULL
> db->pkgcache is not caught, allowing the functions to continue
> instead of exiting.
>
> A later alpm_list_msort() call which uses alpm_list_nth()
> will thus traverse invalid pointers in a non-existent
> db->pkgcache->list.
>
> pmerrno is set to PM_ERR_MEMORY as _alpm_pkghash_create() will
> only return NULL when we run out of memory / exceed max hash
> table size. The local/sync db_populate() functions are also
> exited.
>
> db->pkgcache_loaded is initialized to 0 in _alpm_db_new() as
> this value is used to ascertain the whether db->pkgcache is
> loaded.
Note that this an unnecessary addition; the use of CALLOC guarantees
all fields are zeroed out when we get the chunk of memory. I'll patch
this out when I apply this, the rest looks fine.

> Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
> ---
> *lib/libalpm/be_local.c | * *4 ++++
> *lib/libalpm/be_sync.c *| * *8 +++++++-
> *lib/libalpm/db.c * * * | * *1 +
> *3 files changed, 12 insertions(+), 1 deletions(-)
>
> diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
> index c5b2498..5858270 100644
> --- a/lib/libalpm/be_local.c
> +++ b/lib/libalpm/be_local.c
> @@ -393,6 +393,10 @@ static int local_db_populate(pmdb_t *db)
>
> * * * */* initialize hash at 50% full */
> * * * *db->pkgcache = _alpm_pkghash_create(est_count * 2);
> + * * * if(db->pkgcache == NULL){
> + * * * * * * * closedir(dbdir);
> + * * * * * * * RET_ERR(PM_ERR_MEMORY, -1);
> + * * * }
>
> * * * *while((ent = readdir(dbdir)) != NULL) {
> * * * * * * * *const char *name = ent->d_name;
> diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
> index 4ad045c..4e9b4d3 100644
> --- a/lib/libalpm/be_sync.c
> +++ b/lib/libalpm/be_sync.c
> @@ -234,6 +234,9 @@ static int sync_db_populate(pmdb_t *db)
>
> * * * */* initialize hash at 66% full */
> * * * *db->pkgcache = _alpm_pkghash_create(est_count * 3 / 2);
> + * * * if(db->pkgcache == NULL) {
> + * * * * * * * RET_ERR(PM_ERR_MEMORY, -1);
> + * * * }
>
> * * * *while(archive_read_next_header(archive, &entry) == ARCHIVE_OK) {
> * * * * * * * *const struct stat *st;
> @@ -348,6 +351,9 @@ static int sync_db_read(pmdb_t *db, struct archive *archive,
> * * * *if(likely_pkg && strcmp(likely_pkg->name, pkgname) == 0) {
> * * * * * * * *pkg = likely_pkg;
> * * * *} else {
> + * * * * * * * if(db->pkgcache == NULL) {
> + * * * * * * * * * * * RET_ERR(PM_ERR_MEMORY, -1);
> + * * * * * * * }
> * * * * * * * *pkg = _alpm_pkghash_find(db->pkgcache, pkgname);
> * * * *}
> * * * *if(pkg == NULL) {
> @@ -459,10 +465,10 @@ pmdb_t *_alpm_db_register_sync(const char *treename)
> * * * *_alpm_log(PM_LOG_DEBUG, "registering sync database '%s'
", treename);
>
> * * * *db = _alpm_db_new(treename, 0);
> - * * * db->ops = &sync_db_ops;
> * * * *if(db == NULL) {
> * * * * * * * *RET_ERR(PM_ERR_DB_CREATE, NULL);
> * * * *}
> + * * * db->ops = &sync_db_ops;
>
> * * * *handle->dbs_sync = alpm_list_add(handle->dbs_sync, db);
> * * * *return(db);
> diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
> index 02f8282..d43a16b 100644
> --- a/lib/libalpm/db.c
> +++ b/lib/libalpm/db.c
> @@ -370,6 +370,7 @@ pmdb_t *_alpm_db_new(const char *treename, int is_local)
> * * * *CALLOC(db, 1, sizeof(pmdb_t), RET_ERR(PM_ERR_MEMORY, NULL));
> * * * *STRDUP(db->treename, treename, RET_ERR(PM_ERR_MEMORY, NULL));
> * * * *db->is_local = is_local;
> + * * * db->pkgcache_loaded = 0;
>
> * * * *return(db);
> *}
> --
> 1.7.4
>
>
>