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76980b6399
pam/pam-1.5.1-libpam-support-long-lines.patch
Iker Pedrosa 76980b6399 libpam: support long lines in service files 
Resolves: RHEL-40705

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2024-06-18 12:07:35 +02:00

655 lines
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diff -up Linux-PAM-1.5.1/libpam/pam_handlers.c.libpam-support-long-lines Linux-PAM-1.5.1/libpam/pam_handlers.c
--- Linux-PAM-1.5.1/libpam/pam_handlers.c.libpam-support-long-lines 2020-11-25 17:57:02.000000000 +0100
+++ Linux-PAM-1.5.1/libpam/pam_handlers.c 2024-06-18 10:07:12.434785557 +0200
@@ -17,21 +17,30 @@
#include <fcntl.h>
#include <unistd.h>
-#define BUF_SIZE 1024
#define MODULE_CHUNK 4
#define UNKNOWN_MODULE "<*unknown module*>"
#ifndef _PAM_ISA
#define _PAM_ISA "."
#endif
-static int _pam_assemble_line(FILE *f, char *buf, int buf_len);
+struct line_buffer {
+ char *assembled;
+ char *chunk;
+ size_t chunk_size;
+ size_t len;
+ size_t size;
+};
+
+static void _pam_buffer_init(struct line_buffer *buffer);
+
+static int _pam_assemble_line(FILE *f, struct line_buffer *buf);
static void _pam_free_handlers_aux(struct handler **hp);
static int _pam_add_handler(pam_handle_t *pamh
, int must_fail, int other, int stack_level, int type
, int *actions, const char *mod_path
- , int argc, char **argv, int argvlen);
+ , int argc, char **argv, size_t argvlen);
/* Values for module type */
@@ -59,12 +68,15 @@ static int _pam_parse_conf_file(pam_hand
#endif /* PAM_READ_BOTH_CONFS */
)
{
- char buf[BUF_SIZE];
+ struct line_buffer buffer;
int x; /* read a line from the FILE *f ? */
+
+ _pam_buffer_init(&buffer);
/*
* read a line from the configuration (FILE *) f
*/
- while ((x = _pam_assemble_line(f, buf, BUF_SIZE)) > 0) {
+ while ((x = _pam_assemble_line(f, &buffer)) > 0) {
+ char *buf = buffer.assembled;
char *tok, *nexttok=NULL;
const char *this_service;
const char *mod_path;
@@ -74,7 +86,7 @@ static int _pam_parse_conf_file(pam_hand
int handler_type = PAM_HT_MODULE; /* regular handler from a module */
int argc;
char **argv;
- int argvlen;
+ size_t argvlen;
D(("_pam_init_handler: LINE: %s", buf));
if (known_service != NULL) {
@@ -233,10 +245,11 @@ static int _pam_parse_conf_file(pam_hand
if (nexttok != NULL) {
D(("list: %s",nexttok));
argvlen = _pam_mkargv(nexttok, &argv, &argc);
- D(("argvlen = %d",argvlen));
+ D(("argvlen = %zu",argvlen));
} else { /* there are no arguments so fix by hand */
D(("_pam_init_handlers: empty argument list"));
- argvlen = argc = 0;
+ argvlen = 0;
+ argc = 0;
argv = NULL;
}
@@ -557,88 +570,243 @@ int _pam_init_handlers(pam_handle_t *pam
return PAM_SUCCESS;
}
+static int _pam_buffer_add(struct line_buffer *buffer, char *start, char *end)
+{
+ size_t len = end - start;
+
+ D(("assembled: [%zu/%zu] '%s', adding [%zu] '%s'",
+ buffer->len, buffer->size,
+ buffer->assembled == NULL ? "" : buffer->assembled, len, start));
+
+ if (start == end)
+ return 0;
+
+ if (buffer->assembled == NULL && buffer->chunk == start) {
+ /* no extra allocation needed, just move chunk to assembled */
+ buffer->assembled = buffer->chunk;
+ buffer->len = len;
+ buffer->size = buffer->chunk_size;
+
+ buffer->chunk = NULL;
+ buffer->chunk_size = 0;
+
+ D(("exiting with quick exchange"));
+ return 0;
+ }
+
+ if (buffer->len + len + 1 > buffer->size) {
+ size_t size;
+ char *p;
+
+ size = buffer->len + len + 1;
+ if ((p = realloc(buffer->assembled, size)) == NULL)
+ return -1;
+
+ buffer->assembled = p;
+ buffer->size = size;
+ }
+
+ memcpy(buffer->assembled + buffer->len, start, len);
+ buffer->len += len;
+ buffer->assembled[buffer->len] = '\0';
+
+ D(("exiting"));
+ return 0;
+}
+
+static inline int _pam_buffer_add_eol(struct line_buffer *buffer,
+ char *start, char *end)
+{
+ if (buffer->assembled != NULL || (*start != '\0' && *start != '\n'))
+ return _pam_buffer_add(buffer, start, end);
+ return 0;
+}
+
+static void _pam_buffer_clear(struct line_buffer *buffer)
+{
+ _pam_drop(buffer->assembled);
+ _pam_drop(buffer->chunk);
+ buffer->chunk_size = 0;
+ buffer->len = 0;
+ buffer->size = 0;
+}
+
+static void _pam_buffer_init(struct line_buffer *buffer)
+{
+ buffer->assembled = NULL;
+ buffer->chunk = NULL;
+ _pam_buffer_clear(buffer);
+}
+
+static void _pam_buffer_purge(struct line_buffer *buffer)
+{
+ _pam_drop(buffer->chunk);
+ buffer->chunk_size = 0;
+}
+
+static void _pam_buffer_shift(struct line_buffer *buffer)
+{
+ if (buffer->assembled == NULL)
+ return;
+
+ _pam_buffer_purge(buffer);
+ buffer->chunk = buffer->assembled;
+ buffer->chunk_size = buffer->size;
+
+ buffer->assembled = NULL;
+ buffer->size = 0;
+ buffer->len = 0;
+}
+
+static inline int _pam_buffer_valid(struct line_buffer *buffer)
+{
+ return buffer->assembled != NULL && *buffer->assembled != '\0';
+}
+
+/*
+ * Trim string to relevant parts of a configuration line.
+ *
+ * Preceding whitespaces are skipped and comment (#) marks the end of
+ * configuration line.
+ *
+ * Returns start of configuration line.
+ */
+static inline char *_pam_str_trim(char *str)
+{
+ /* skip leading spaces */
+ str += strspn(str, " \t");
+ /*
+ * we are only interested in characters before the first '#'
+ * character
+ */
+ str[strcspn(str, "#")] = '\0';
+
+ return str;
+}
+
+/*
+ * Remove escaped newline from end of string.
+ *
+ * Configuration lines may span across multiple lines in a file
+ * by ending a line with a backslash (\).
+ *
+ * If an escaped newline is encountered, the backslash will be
+ * replaced with a blank ' ' and the newline itself removed.
+ * Then the variable "end" will point to the new end of line.
+ *
+ * Returns 0 if escaped newline was found and replaced, 1 otherwise.
+ */
+static inline int _pam_str_unescnl(char *start, char **end)
+{
+ int ret = 1;
+ char *p = *end;
+
+ /*
+ * Check for backslash by scanning back from the end of
+ * the entered line, the '\n' should be included since
+ * normally a line is terminated with this character.
+ */
+ while (p > start && ((*--p == ' ') || (*p == '\t') || (*p == '\n')))
+ ;
+ if (*p == '\\') {
+ *p++ = ' '; /* replace backslash with ' ' */
+ *p = '\0'; /* truncate the line here */
+ *end = p;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * Prepare line from file for configuration line parsing.
+ *
+ * A configuration line may span across multiple lines in a file.
+ * Remove comments and skip preceding whitespaces.
+ *
+ * Returns 0 if line spans across multiple lines, 1 if
+ * end of line is encountered.
+ */
+static inline int _pam_str_prepare(char *line, ssize_t len,
+ char **start, char **end)
+{
+ int ret;
+
+ *start = line;
+ *end = line + len;
+
+ ret = _pam_str_unescnl(*start, end) || strchr(*start, '#') != NULL;
+
+ *start = _pam_str_trim(*start);
+
+ return ret;
+}
+
/*
* This is where we read a line of the PAM config file. The line may be
* preceded by lines of comments and also extended with "\\\n"
+ *
+ * Returns 0 on EOF, 1 on successful line parsing, or -1 on error.
*/
-static int _pam_assemble_line(FILE *f, char *buffer, int buf_len)
+static int _pam_assemble_line(FILE *f, struct line_buffer *buffer)
{
- char *p = buffer;
- char *endp = buffer + buf_len;
- char *s, *os;
- int used = 0;
+ int ret = 0;
/* loop broken with a 'break' when a non-'\\n' ended line is read */
D(("called."));
+
+ _pam_buffer_shift(buffer);
+
for (;;) {
- if (p >= endp) {
- /* Overflow */
- D(("_pam_assemble_line: overflow"));
- return -1;
- }
- if (fgets(p, endp - p, f) == NULL) {
- if (used) {
+ char *start, *end;
+ ssize_t n;
+ int eol;
+
+ if ((n = getline(&buffer->chunk, &buffer->chunk_size, f)) == -1) {
+ if (ret) {
/* Incomplete read */
- return -1;
+ ret = -1;
} else {
/* EOF */
- return 0;
+ ret = 0;
}
+ break;
}
- /* skip leading spaces --- line may be blank */
-
- s = p + strspn(p, " \n\t");
- if (*s && (*s != '#')) {
- os = s;
-
- /*
- * we are only interested in characters before the first '#'
- * character
- */
-
- while (*s && *s != '#')
- ++s;
- if (*s == '#') {
- *s = '\0';
- used += strlen(os);
- break; /* the line has been read */
- }
-
- s = os;
-
- /*
- * Check for backslash by scanning back from the end of
- * the entered line, the '\n' has been included since
- * normally a line is terminated with this
- * character. fgets() should only return one though!
- */
-
- s += strlen(s);
- while (s > os && ((*--s == ' ') || (*s == '\t')
- || (*s == '\n')));
-
- /* check if it ends with a backslash */
- if (*s == '\\') {
- *s++ = ' '; /* replace backslash with ' ' */
- *s = '\0'; /* truncate the line here */
- used += strlen(os);
- p = s; /* there is more ... */
- } else {
- /* End of the line! */
- used += strlen(os);
- break; /* this is the complete line */
- }
+ eol = _pam_str_prepare(buffer->chunk, n, &start, &end);
+ if (eol) {
+ if (_pam_buffer_add_eol(buffer, start, end)) {
+ ret = -1;
+ break;
+ }
+ if (_pam_buffer_valid(buffer)) {
+ /* Successfully parsed a line */
+ ret = 1;
+ break;
+ }
+ /* Start parsing next line */
+ _pam_buffer_shift(buffer);
+ ret = 0;
} else {
- /* Nothing in this line */
- /* Don't move p */
+ /* Configuration line spans across multiple lines in file */
+ if (_pam_buffer_add(buffer, start, end)) {
+ ret = -1;
+ break;
+ }
+ /* Keep parsing line */
+ ret = 1;
}
}
- return used;
+ if (ret == 1)
+ _pam_buffer_purge(buffer);
+ else
+ _pam_buffer_clear(buffer);
+
+ return ret;
}
static char *
@@ -777,7 +945,7 @@ _pam_load_module(pam_handle_t *pamh, con
int _pam_add_handler(pam_handle_t *pamh
, int handler_type, int other, int stack_level, int type
, int *actions, const char *mod_path
- , int argc, char **argv, int argvlen)
+ , int argc, char **argv, size_t argvlen)
{
struct loaded_module *mod = NULL;
struct handler **handler_p;
diff -up Linux-PAM-1.5.1/libpam/pam_misc.c.libpam-support-long-lines Linux-PAM-1.5.1/libpam/pam_misc.c
--- Linux-PAM-1.5.1/libpam/pam_misc.c.libpam-support-long-lines 2024-06-18 09:52:38.726482849 +0200
+++ Linux-PAM-1.5.1/libpam/pam_misc.c 2024-06-18 10:02:13.132973447 +0200
@@ -39,6 +39,8 @@
#include <stdarg.h>
#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
@@ -163,60 +164,55 @@ char *_pam_memdup(const char *x, int len
/* Generate argv, argc from s */
/* caller must free(argv) */
-int _pam_mkargv(const char *s, char ***argv, int *argc)
+size_t _pam_mkargv(const char *s, char ***argv, int *argc)
{
- int l;
- int argvlen = 0;
- char *sbuf, *sbuf_start;
+ size_t l;
+ size_t argvlen = 0;
char **our_argv = NULL;
- char **argvbuf;
- char *argvbufp;
-#ifdef PAM_DEBUG
- int count=0;
-#endif
- D(("_pam_mkargv called: %s",s));
+ D(("called: %s",s));
*argc = 0;
l = strlen(s);
- if (l) {
- if ((sbuf = sbuf_start = _pam_strdup(s)) == NULL) {
- pam_syslog(NULL, LOG_CRIT,
- "pam_mkargv: null returned by _pam_strdup");
- D(("arg NULL"));
+ if (l && l < SIZE_MAX / (sizeof(char) + sizeof(char *))) {
+ char **argvbuf;
+ /* Overkill on the malloc, but not large */
+ argvlen = (l + 1) * (sizeof(char) + sizeof(char *));
+ if ((our_argv = argvbuf = malloc(argvlen)) == NULL) {
+ pam_syslog(NULL, LOG_CRIT, "pam_mkargv: null returned by malloc");
+ argvlen = 0;
} else {
- /* Overkill on the malloc, but not large */
- argvlen = (l + 1) * ((sizeof(char)) + sizeof(char *));
- if ((our_argv = argvbuf = malloc(argvlen)) == NULL) {
- pam_syslog(NULL, LOG_CRIT,
- "pam_mkargv: null returned by malloc");
- } else {
- char *tmp=NULL;
-
- argvbufp = (char *) argvbuf + (l * sizeof(char *));
- D(("[%s]",sbuf));
- while ((sbuf = _pam_StrTok(sbuf, " \n\t", &tmp))) {
- D(("arg #%d",++count));
- D(("->[%s]",sbuf));
- strcpy(argvbufp, sbuf);
- D(("copied token"));
- *argvbuf = argvbufp;
- argvbufp += strlen(argvbufp) + 1;
- D(("stepped in argvbufp"));
- (*argc)++;
- argvbuf++;
- sbuf = NULL;
- D(("loop again?"));
+ char *argvbufp;
+ char *tmp=NULL;
+ char *tok;
+#ifdef PAM_DEBUG
+ unsigned count=0;
+#endif
+ argvbufp = (char *) argvbuf + (l * sizeof(char *));
+ strcpy(argvbufp, s);
+ D(("[%s]",argvbufp));
+ while ((tok = _pam_StrTok(argvbufp, " \n\t", &tmp))) {
+ D(("arg #%u",++count));
+ D(("->[%s]",tok));
+ *argvbuf++ = tok;
+ if (*argc == INT_MAX) {
+ pam_syslog(NULL, LOG_CRIT,
+ "pam_mkargv: too many arguments");
+ argvlen = 0;
+ _pam_drop(our_argv);
+ break;
}
+ (*argc)++;
+ argvbufp = NULL;
+ D(("loop again?"));
}
- _pam_drop(sbuf_start);
}
}
*argv = our_argv;
- D(("_pam_mkargv returned"));
+ D(("exiting"));
return(argvlen);
}
diff -up Linux-PAM-1.5.1/libpam/pam_private.h.libpam-support-long-lines Linux-PAM-1.5.1/libpam/pam_private.h
--- Linux-PAM-1.5.1/libpam/pam_private.h.libpam-support-long-lines 2020-11-25 17:57:02.000000000 +0100
+++ Linux-PAM-1.5.1/libpam/pam_private.h 2024-06-18 09:52:38.726482849 +0200
@@ -16,6 +16,7 @@
#include "config.h"
+#include <stddef.h>
#include <syslog.h>
#include <security/pam_appl.h>
@@ -272,7 +273,7 @@ char *_pam_strdup(const char *s);
char *_pam_memdup(const char *s, int len);
-int _pam_mkargv(const char *s, char ***argv, int *argc);
+size_t _pam_mkargv(const char *s, char ***argv, int *argc);
void _pam_sanitize(pam_handle_t *pamh);
diff -up Linux-PAM-1.5.1/modules/pam_exec/pam_exec.c.libpam-support-long-lines Linux-PAM-1.5.1/modules/pam_exec/pam_exec.c
--- Linux-PAM-1.5.1/modules/pam_exec/pam_exec.c.libpam-support-long-lines 2020-11-25 17:57:02.000000000 +0100
+++ Linux-PAM-1.5.1/modules/pam_exec/pam_exec.c 2024-06-18 09:52:38.725482846 +0200
@@ -407,7 +407,7 @@ call_exec (const char *pam_type, pam_han
_exit (err);
}
- arggv = calloc (argc + 4, sizeof (char *));
+ arggv = calloc ((size_t) argc + 1, sizeof (char *));
if (arggv == NULL)
_exit (ENOMEM);
diff -up Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c.libpam-support-long-lines Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c
--- Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c.libpam-support-long-lines 2024-06-18 09:52:38.725482846 +0200
+++ Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c 2024-06-18 09:54:17.102732759 +0200
@@ -96,7 +96,8 @@ static int process_args(pam_handle_t *pa
char **levp;
const char *user = NULL;
const void *tmp;
- int i,size, retval;
+ int i, retval;
+ size_t size;
*filtername = *++argv;
if (ctrl & FILTER_DEBUG) {
diff -up Linux-PAM-1.5.1/modules/pam_motd/pam_motd.c.libpam-support-long-lines Linux-PAM-1.5.1/modules/pam_motd/pam_motd.c
--- Linux-PAM-1.5.1/modules/pam_motd/pam_motd.c.libpam-support-long-lines 2020-11-25 17:57:02.000000000 +0100
+++ Linux-PAM-1.5.1/modules/pam_motd/pam_motd.c 2024-06-18 09:55:44.530954883 +0200
@@ -71,14 +71,14 @@ static void try_to_display_fd(pam_handle
* Returns 0 in case of error, 1 in case of success.
*/
static int pam_split_string(const pam_handle_t *pamh, char *arg, char delim,
- char ***out_arg_split, unsigned int *out_num_strs)
+ char ***out_arg_split, size_t *out_num_strs)
{
char *arg_extracted = NULL;
const char *arg_ptr = arg;
char **arg_split = NULL;
char delim_str[2];
- unsigned int i = 0;
- unsigned int num_strs = 0;
+ size_t i = 0;
+ size_t num_strs = 0;
int retval = 0;
delim_str[0] = delim;
@@ -172,13 +172,13 @@ static int filter_dirents(const struct d
}
static void try_to_display_directories_with_overrides(pam_handle_t *pamh,
- char **motd_dir_path_split, unsigned int num_motd_dirs, int report_missing)
+ char **motd_dir_path_split, size_t num_motd_dirs, int report_missing)
{
struct dirent ***dirscans = NULL;
unsigned int *dirscans_sizes = NULL;
unsigned int dirscans_size_total = 0;
char **dirnames_all = NULL;
- unsigned int i;
+ size_t i;
int i_dirnames = 0;
if (pamh == NULL || motd_dir_path_split == NULL) {
@@ -304,9 +304,8 @@ static int drop_privileges(pam_handle_t
}
static int try_to_display(pam_handle_t *pamh, char **motd_path_split,
- unsigned int num_motd_paths,
- char **motd_dir_path_split,
- unsigned int num_motd_dir_paths, int report_missing)
+ size_t num_motd_paths, char **motd_dir_path_split,
+ size_t num_motd_dir_paths, int report_missing)
{
PAM_MODUTIL_DEF_PRIVS(privs);
@@ -316,7 +315,7 @@ static int try_to_display(pam_handle_t *
}
if (motd_path_split != NULL) {
- unsigned int i;
+ size_t i;
for (i = 0; i < num_motd_paths; i++) {
int fd = open(motd_path_split[i], O_RDONLY, 0);
@@ -354,11 +353,11 @@ int pam_sm_open_session(pam_handle_t *pa
int retval = PAM_IGNORE;
const char *motd_path = NULL;
char *motd_path_copy = NULL;
- unsigned int num_motd_paths = 0;
+ size_t num_motd_paths = 0;
char **motd_path_split = NULL;
const char *motd_dir_path = NULL;
char *motd_dir_path_copy = NULL;
- unsigned int num_motd_dir_paths = 0;
+ size_t num_motd_dir_paths = 0;
char **motd_dir_path_split = NULL;
int report_missing;
diff -up Linux-PAM-1.5.1/modules/pam_permit/tst-pam_permit-retval.c.libpam-support-long-lines Linux-PAM-1.5.1/modules/pam_permit/tst-pam_permit-retval.c
--- Linux-PAM-1.5.1/modules/pam_permit/tst-pam_permit-retval.c.libpam-support-long-lines 2020-11-25 17:57:02.000000000 +0100
+++ Linux-PAM-1.5.1/modules/pam_permit/tst-pam_permit-retval.c 2024-06-18 09:52:38.726482849 +0200
@@ -52,6 +52,35 @@ main(void)
ASSERT_EQ(PAM_SUCCESS, pam_end(pamh, 0));
pamh = NULL;
+ /* Perform a test dedicated to configuration file parsing. */
+ ASSERT_NE(NULL, fp = fopen(service_file, "w"));
+ ASSERT_LT(0, fprintf(fp, "#%%PAM-1.0\n"
+ "# ignore escaped newlines in comments \\\n"
+ "auth required \\\n"
+ " %s/.libs/%s.so\n"
+ "# allow unneeded whitespaces\n"
+ " account required %s/.libs/%s.so%c\\\n"
+ "line after NUL byte continues up to here\n"
+ "password required %s/.libs/%s.so # eol comment\n"
+ "session required %s/.libs/%s.so",
+ cwd, MODULE_NAME,
+ cwd, MODULE_NAME, '\0',
+ cwd, MODULE_NAME,
+ cwd, MODULE_NAME));
+ ASSERT_EQ(0, fclose(fp));
+
+ ASSERT_EQ(PAM_SUCCESS,
+ pam_start_confdir(service_file, user_name, &conv, ".", &pamh));
+ ASSERT_NE(NULL, pamh);
+ ASSERT_EQ(PAM_SUCCESS, pam_authenticate(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_setcred(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_acct_mgmt(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_chauthtok(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_open_session(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_close_session(pamh, 0));
+ ASSERT_EQ(PAM_SUCCESS, pam_end(pamh, 0));
+ pamh = NULL;
+
ASSERT_EQ(0, unlink(service_file));
return 0;
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