diff options
Diffstat (limited to 'contrib')
| -rw-r--r-- | contrib/pam_zfs_key/pam_zfs_key.c | 48 |
1 files changed, 22 insertions, 26 deletions
diff --git a/contrib/pam_zfs_key/pam_zfs_key.c b/contrib/pam_zfs_key/pam_zfs_key.c index e4196b7ad..dead090f9 100644 --- a/contrib/pam_zfs_key/pam_zfs_key.c +++ b/contrib/pam_zfs_key/pam_zfs_key.c @@ -41,6 +41,7 @@ #if defined(__linux__) #include <security/pam_ext.h> +#define MAP_FLAGS MAP_PRIVATE | MAP_ANONYMOUS #elif defined(__FreeBSD__) #include <security/pam_appl.h> static void @@ -51,6 +52,7 @@ pam_syslog(pam_handle_t *pamh, int loglevel, const char *fmt, ...) vsyslog(loglevel, fmt, args); va_end(args); } +#define MAP_FLAGS MAP_PRIVATE | MAP_ANON | MAP_NOCORE #endif #include <string.h> @@ -77,9 +79,9 @@ typedef struct { } pw_password_t; /* - * Try to mlock or munlock addr while handling EAGAIN by retrying ten times - * and sleeping 10 milliseconds in between for a total of 0.1 seconds. - * lock_func must point to either mlock(2) or munlock(2). + * Try to mlock(2) or munlock(2) addr while handling EAGAIN by retrying ten + * times and sleeping 10 milliseconds in between for a total of 0.1 + * seconds. lock_func must point to either mlock(2) or munlock(2). */ static int try_lock(mlock_func_t lock_func, const void *addr, size_t len) @@ -110,18 +112,25 @@ alloc_pw_size(size_t len) } pw->len = len; /* - * The use of malloc() triggers a spurious gcc 11 -Wmaybe-uninitialized - * warning in the mlock() function call below, so use calloc(). + * We use mmap(2) rather than malloc(3) since later on we mlock(2) the + * memory region. Since mlock(2) and munlock(2) operate on whole memory + * pages we should allocate a whole page here as mmap(2) does. Further + * this ensures that the addresses passed to mlock(2) an munlock(2) are + * on a page boundary as suggested by FreeBSD and required by some + * other implementations. Finally we avoid inadvertently munlocking + * memory mlocked by an concurrently running instance of us. */ - pw->value = calloc(len, 1); - if (!pw->value) { + pw->value = mmap(NULL, pw->len, PROT_READ | PROT_WRITE, MAP_FLAGS, + -1, 0); + + if (pw->value == MAP_FAILED) { free(pw); return (NULL); } if (try_lock(mlock, pw->value, pw->len) != 0) { - free(pw->value); + (void) munmap(pw->value, pw->len); free(pw); - return NULL; + return (NULL); } return (pw); } @@ -129,25 +138,12 @@ alloc_pw_size(size_t len) static pw_password_t * alloc_pw_string(const char *source) { - pw_password_t *pw = malloc(sizeof (pw_password_t)); + size_t len = strlen(source) + 1; + pw_password_t *pw = alloc_pw_size(len); + if (!pw) { return (NULL); } - pw->len = strlen(source) + 1; - /* - * The use of malloc() triggers a spurious gcc 11 -Wmaybe-uninitialized - * warning in the mlock() function call below, so use calloc(). - */ - pw->value = calloc(pw->len, 1); - if (!pw->value) { - free(pw); - return (NULL); - } - if (try_lock(mlock, pw->value, pw->len) != 0) { - free(pw->value); - free(pw); - return NULL; - } memcpy(pw->value, source, pw->len); return (pw); } @@ -157,7 +153,7 @@ pw_free(pw_password_t *pw) { bzero(pw->value, pw->len); if (try_lock(munlock, pw->value, pw->len) == 0) { - free(pw->value); + (void) munmap(pw->value, pw->len); } free(pw); } |