patch/patch-2.7.6-crash-RLIMIT_NOFILE.patch
Than Ngo 9dc0ea4960 - backported patch, abort when cleaning up fails
- backported patch, improve support for memory leak detection
- backported patch, don't crash when RLIMIT_NOFILE is set to RLIM_INFINITY
- backported patch, CVE-2019-13636, don't follow symlinks unless --follow-symlinks is given
- backported patch, avoid invalid memory accessin context format diffs
- backported patch, fix failed assertion
2019-07-24 15:05:07 +02:00

85 lines
2.9 KiB
Diff

commit 61d7788b83b302207a67b82786f4fd79e3538f30
Author: Andreas Gruenbacher <agruen@gnu.org>
Date: Thu Jun 27 11:10:43 2019 +0200
Don't crash when RLIMIT_NOFILE is set to RLIM_INFINITY
* src/safe.c (min_cached_fds): Define minimum number of cached dir file
descriptors.
(max_cached_fds): Change type to rlim_t to allow storing RLIM_INFINITY.
(init_dirfd_cache): Set max_cached_fds to RLIM_INFINITY when RLIMIT_NOFILE is
RLIM_INFINITY. Set the initial hash table size to min_cached_fds, independent
of RLIMIT_NOFILE: patches commonly only affect one or a few files, so a small
hash table will usually suffice; if needed, the hash table will grow.
(insert_cached_dirfd): Don't shrink the cache when max_cached_fds is
RLIM_INFINITY.
diff --git a/src/safe.c b/src/safe.c
index 5a7202f..f147b0e 100644
--- a/src/safe.c
+++ b/src/safe.c
@@ -67,7 +67,8 @@ struct cached_dirfd {
};
static Hash_table *cached_dirfds = NULL;
-static size_t max_cached_fds;
+static rlim_t min_cached_fds = 8;
+static rlim_t max_cached_fds;
LIST_HEAD (lru_list);
static size_t hash_cached_dirfd (const void *entry, size_t table_size)
@@ -98,11 +99,17 @@ static void init_dirfd_cache (void)
{
struct rlimit nofile;
- max_cached_fds = 8;
if (getrlimit (RLIMIT_NOFILE, &nofile) == 0)
- max_cached_fds = MAX (nofile.rlim_cur / 4, max_cached_fds);
+ {
+ if (nofile.rlim_cur == RLIM_INFINITY)
+ max_cached_fds = RLIM_INFINITY;
+ else
+ max_cached_fds = MAX (nofile.rlim_cur / 4, min_cached_fds);
+ }
+ else
+ max_cached_fds = min_cached_fds;
- cached_dirfds = hash_initialize (max_cached_fds,
+ cached_dirfds = hash_initialize (min_cached_fds,
NULL,
hash_cached_dirfd,
compare_cached_dirfds,
@@ -148,20 +155,23 @@ static void insert_cached_dirfd (struct cached_dirfd *entry, int keepfd)
if (cached_dirfds == NULL)
init_dirfd_cache ();
- /* Trim off the least recently used entries */
- while (hash_get_n_entries (cached_dirfds) >= max_cached_fds)
+ if (max_cached_fds != RLIM_INFINITY)
{
- struct cached_dirfd *last =
- list_entry (lru_list.prev, struct cached_dirfd, lru_link);
- if (&last->lru_link == &lru_list)
- break;
- if (last->fd == keepfd)
+ /* Trim off the least recently used entries */
+ while (hash_get_n_entries (cached_dirfds) >= max_cached_fds)
{
- last = list_entry (last->lru_link.prev, struct cached_dirfd, lru_link);
+ struct cached_dirfd *last =
+ list_entry (lru_list.prev, struct cached_dirfd, lru_link);
if (&last->lru_link == &lru_list)
break;
+ if (last->fd == keepfd)
+ {
+ last = list_entry (last->lru_link.prev, struct cached_dirfd, lru_link);
+ if (&last->lru_link == &lru_list)
+ break;
+ }
+ remove_cached_dirfd (last);
}
- remove_cached_dirfd (last);
}
/* Only insert if the parent still exists. */