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author | 2018-06-25 17:10:15 +0200 | |
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committer | 2018-06-25 17:10:15 +0200 | |
commit | 318bad78b084cd510c7b672a1a0859c0df08dbb7 (patch) | |
tree | 530b33b954bef36b1fc0b55475c46c9700ec65f0 /nscd | |
parent | csb_PL: Add alternative month names (bug 23140). (diff) | |
download | glibc-318bad78b084cd510c7b672a1a0859c0df08dbb7.tar.gz glibc-318bad78b084cd510c7b672a1a0859c0df08dbb7.tar.bz2 glibc-318bad78b084cd510c7b672a1a0859c0df08dbb7.zip |
nscd restart: Use malloc instead of extend_alloca [BZ #18023]
This introduces a separate function, read_cmdline, which reads the
contents of /proc/self/cmdline into a heap-allocated buffer.
Diffstat (limited to 'nscd')
-rw-r--r-- | nscd/connections.c | 99 |
1 files changed, 61 insertions, 38 deletions
diff --git a/nscd/connections.c b/nscd/connections.c index 1b3bae4eeb..47fbb9923a 100644 --- a/nscd/connections.c +++ b/nscd/connections.c @@ -1281,64 +1281,83 @@ request from '%s' [%ld] not handled due to missing permission"), } } - -/* Restart the process. */ -static void -restart (void) +static char * +read_cmdline (size_t *size) { - /* First determine the parameters. We do not use the parameters - passed to main() since in case nscd is started by running the - dynamic linker this will not work. Yes, this is not the usual - case but nscd is part of glibc and we occasionally do this. */ - size_t buflen = 1024; - char *buf = alloca (buflen); - size_t readlen = 0; int fd = open ("/proc/self/cmdline", O_RDONLY); - if (fd == -1) + if (fd < 0) + return NULL; + size_t current = 0; + size_t limit = 1024; + char *buffer = malloc (limit); + if (buffer == NULL) { - dbg_log (_("\ -cannot open /proc/self/cmdline: %s; disabling paranoia mode"), - strerror (errno)); - - paranoia = 0; - return; + close (fd); + errno = ENOMEM; + return NULL; } - while (1) { - ssize_t n = TEMP_FAILURE_RETRY (read (fd, buf + readlen, - buflen - readlen)); - if (n == -1) + if (current == limit) { - dbg_log (_("\ -cannot read /proc/self/cmdline: %s; disabling paranoia mode"), - strerror (errno)); + char *newptr; + if (2 * limit < limit + || (newptr = realloc (buffer, 2 * limit)) == NULL) + { + free (buffer); + close (fd); + errno = ENOMEM; + return NULL; + } + buffer = newptr; + limit *= 2; + } + ssize_t n = TEMP_FAILURE_RETRY (read (fd, buffer + current, + limit - current)); + if (n == -1) + { + int e = errno; + free (buffer); close (fd); - paranoia = 0; - return; + errno = e; + return NULL; } - - readlen += n; - - if (readlen < buflen) + if (n == 0) break; - - /* We might have to extend the buffer. */ - size_t old_buflen = buflen; - char *newp = extend_alloca (buf, buflen, 2 * buflen); - buf = memmove (newp, buf, old_buflen); + current += n; } close (fd); + *size = current; + return buffer; +} + + +/* Restart the process. */ +static void +restart (void) +{ + /* First determine the parameters. We do not use the parameters + passed to main because then nscd would use the system libc after + restarting even if it was started by a non-system dynamic linker + during glibc testing. */ + size_t readlen; + char *cmdline = read_cmdline (&readlen); + if (cmdline == NULL) + { + dbg_log (_("\ +cannot open /proc/self/cmdline: %m; disabling paranoia mode")); + paranoia = 0; + return; + } /* Parse the command line. Worst case scenario: every two characters form one parameter (one character plus NUL). */ char **argv = alloca ((readlen / 2 + 1) * sizeof (argv[0])); int argc = 0; - char *cp = buf; - while (cp < buf + readlen) + for (char *cp = cmdline; cp < cmdline + readlen;) { argv[argc++] = cp; cp = (char *) rawmemchr (cp, '\0') + 1; @@ -1355,6 +1374,7 @@ cannot change to old UID: %s; disabling paranoia mode"), strerror (errno)); paranoia = 0; + free (cmdline); return; } @@ -1366,6 +1386,7 @@ cannot change to old GID: %s; disabling paranoia mode"), ignore_value (setuid (server_uid)); paranoia = 0; + free (cmdline); return; } } @@ -1383,6 +1404,7 @@ cannot change to old working directory: %s; disabling paranoia mode"), ignore_value (setgid (server_gid)); } paranoia = 0; + free (cmdline); return; } @@ -1431,6 +1453,7 @@ cannot change to old working directory: %s; disabling paranoia mode"), dbg_log (_("cannot change current working directory to \"/\": %s"), strerror (errno)); paranoia = 0; + free (cmdline); /* Reenable the databases. */ time_t now = time (NULL); |