From: Yuriy M. Kaminskiy Date: Sat, 27 Feb 2016 16:27:29 +0000 (+0300) Subject: misc: safer (and uniform) handling of return value X-Git-Tag: v2.28-rc1~60 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=06fa5817489adb9728f8a29d4cb7602fb48b8bdb;p=thirdparty%2Futil-linux.git misc: safer (and uniform) handling of return value When `rc` is `INT_MAX`, `rc + 1` result in signed integer overflow. Signed-off-by: Karel Zak --- diff --git a/disk-utils/fsck.c b/disk-utils/fsck.c index b4630c5411..6f9e78b342 100644 --- a/disk-utils/fsck.c +++ b/disk-utils/fsck.c @@ -316,7 +316,7 @@ static int is_irrotational_disk(dev_t disk) "/sys/dev/block/%d:%d/queue/rotational", major(disk), minor(disk)); - if (rc < 0 || (unsigned int) (rc + 1) > sizeof(path)) + if (rc < 0 || (unsigned int) rc >= sizeof(path)) return 0; f = fopen(path, "r"); diff --git a/lib/at.c b/lib/at.c index f7074bb74d..4086a2541e 100644 --- a/lib/at.c +++ b/lib/at.c @@ -31,7 +31,7 @@ int fstat_at(int dir __attribute__ ((__unused__)), const char *dirname, int len; len = snprintf(path, sizeof(path), "%s/%s", dirname, filename); - if (len < 0 || len + 1 > sizeof(path)) + if (len < 0 || (size_t)len >= sizeof(path)) return -1; return nofollow ? lstat(path, st) : stat(path, st); @@ -56,7 +56,7 @@ int open_at(int dir __attribute__((__unused__)), const char *dirname, int len; len = snprintf(path, sizeof(path), "%s/%s", dirname, filename); - if (len < 0 || len + 1 > sizeof(path)) + if (len < 0 || (size_t)len >= sizeof(path)) return -1; return open(path, flags); @@ -91,7 +91,7 @@ ssize_t readlink_at(int dir __attribute__((__unused__)), const char *dirname, int len; len = snprintf(path, sizeof(path), "%s/%s", dirname, pathname); - if (len < 0 || len + 1 > sizeof(path)) + if (len < 0 || (size_t)len >= sizeof(path)) return -1; return readlink(path, buf, bufsiz); diff --git a/lib/cpuset.c b/lib/cpuset.c index 41c0eed470..7445ab4378 100644 --- a/lib/cpuset.c +++ b/lib/cpuset.c @@ -177,13 +177,10 @@ char *cpulist_create(char *str, size_t len, rlen = snprintf(ptr, len, "%zu-%zu,", i, i + run); i += run; } - if (rlen < 0 || (size_t) rlen + 1 > len) + if (rlen < 0 || (size_t) rlen >= len) return NULL; ptr += rlen; - if (rlen > 0 && len > (size_t) rlen) - len -= rlen; - else - len = 0; + len -= rlen; } } ptr -= entry_made; diff --git a/lib/sysfs.c b/lib/sysfs.c index 9d76148809..b6e0b7230e 100644 --- a/lib/sysfs.c +++ b/lib/sysfs.c @@ -26,7 +26,7 @@ char *sysfs_devno_attribute_path(dev_t devno, char *buf, len = snprintf(buf, bufsiz, _PATH_SYS_DEVBLOCK "/%d:%d", major(devno), minor(devno)); - return (len < 0 || (size_t) len + 1 > bufsiz) ? NULL : buf; + return (len < 0 || (size_t) len >= bufsiz) ? NULL : buf; } int sysfs_devno_has_attribute(dev_t devno, const char *attr) @@ -82,7 +82,7 @@ dev_t sysfs_devname_to_devno(const char *name, const char *parent) _PATH_SYS_BLOCK "/%s/%s/dev", _parent, _name); free(_name); free(_parent); - if (len < 0 || (size_t) len + 1 > sizeof(buf)) + if (len < 0 || (size_t) len >= sizeof(buf)) return 0; path = buf; @@ -100,7 +100,7 @@ dev_t sysfs_devname_to_devno(const char *name, const char *parent) len = snprintf(buf, sizeof(buf), _PATH_SYS_BLOCK "/%s/dev", _name); free(_name); - if (len < 0 || (size_t) len + 1 > sizeof(buf)) + if (len < 0 || (size_t) len >= sizeof(buf)) return 0; path = buf; } @@ -463,7 +463,7 @@ int sysfs_write_u64(struct sysfs_cxt *cxt, const char *attr, uint64_t num) return -errno; len = snprintf(buf, sizeof(buf), "%" PRIu64, num); - if (len < 0 || (size_t) len + 1 > sizeof(buf)) + if (len < 0 || (size_t) len >= sizeof(buf)) rc = len < 0 ? -errno : -E2BIG; else rc = write_all(fd, buf, len); @@ -930,7 +930,7 @@ static char *sysfs_scsi_host_attribute_path(struct sysfs_cxt *cxt, len = snprintf(buf, bufsz, _PATH_SYS_CLASS "/%s_host/host%d", type, host); - return (len < 0 || (size_t) len + 1 > bufsz) ? NULL : buf; + return (len < 0 || (size_t) len >= bufsz) ? NULL : buf; } char *sysfs_scsi_host_strdup_attribute(struct sysfs_cxt *cxt, @@ -979,7 +979,7 @@ static char *sysfs_scsi_attribute_path(struct sysfs_cxt *cxt, else len = snprintf(buf, bufsz, _PATH_SYS_SCSI "/devices/%d:%d:%d:%d", h,c,t,l); - return (len < 0 || (size_t) len + 1 > bufsz) ? NULL : buf; + return (len < 0 || (size_t) len >= bufsz) ? NULL : buf; } int sysfs_scsi_has_attribute(struct sysfs_cxt *cxt, const char *attr) diff --git a/libfdisk/src/ask.c b/libfdisk/src/ask.c index 7d55b5488f..225957f343 100644 --- a/libfdisk/src/ask.c +++ b/libfdisk/src/ask.c @@ -383,15 +383,11 @@ static char *mk_string_list(char *ptr, size_t *len, size_t *begin, snprintf(ptr, *len, "%c-%c,", tochar(*begin), tochar(*begin + *run)) : snprintf(ptr, *len, "%zu-%zu,", *begin, *begin + *run); - if (rlen < 0 || (size_t) rlen + 1 > *len) + if (rlen < 0 || (size_t) rlen >= *len) return NULL; ptr += rlen; - - if (rlen > 0 && *len > (size_t) rlen) - *len -= rlen; - else - *len = 0; + *len -= rlen; if (cur == -1 && *begin) { /* end of the list */ diff --git a/login-utils/login.c b/login-utils/login.c index c5ce1887ee..ac76f65630 100644 --- a/login-utils/login.c +++ b/login-utils/login.c @@ -1057,7 +1057,7 @@ static void init_environ(struct login_context *cxt) /* mailx will give a funny error msg if you forget this one */ len = snprintf(tmp, sizeof(tmp), "%s/%s", _PATH_MAILDIR, pwd->pw_name); - if (len > 0 && (size_t) len + 1 <= sizeof(tmp)) + if (len > 0 && (size_t) len < sizeof(tmp)) setenv("MAIL", tmp, 0); /* LOGNAME is not documented in login(1) but HP-UX 6.5 does it. We'll diff --git a/login-utils/lslogins.c b/login-utils/lslogins.c index f9b9d401d8..40a1343088 100644 --- a/login-utils/lslogins.c +++ b/login-utils/lslogins.c @@ -397,7 +397,7 @@ again: x = snprintf(p, len, "%s,", grp->gr_name); } - if (x < 0 || (size_t) x + 1 > len) { + if (x < 0 || (size_t) x >= len) { size_t cur = p - res; maxlen *= 2; diff --git a/misc-utils/cal.c b/misc-utils/cal.c index b7f38275c4..c687c6c9d1 100644 --- a/misc-utils/cal.c +++ b/misc-utils/cal.c @@ -514,10 +514,15 @@ static void headers_init(struct cal_control *ctl) size_t i, wd; char *cur_dh = day_headings; char tmp[FMT_ST_CHARS]; - size_t year_len; + int year_len; year_len = snprintf(tmp, sizeof(tmp), "%d", ctl->req.year); + if (year_len < 0 || (size_t)year_len >= sizeof(tmp)) { + /* XXX impossible error */ + return; + } + for (i = 0; i < DAYS_IN_WEEK; i++) { size_t space_left; wd = (i + ctl->weekstart) % DAYS_IN_WEEK; diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c index 318249fe02..fc327623b1 100644 --- a/sys-utils/lscpu.c +++ b/sys-utils/lscpu.c @@ -1273,12 +1273,14 @@ get_cell_data(struct lscpu_desc *desc, int idx, int col, if (cpuset_ary_isset(cpu, ca->sharedmaps, ca->nsharedmaps, setsize, &i) == 0) { int x = snprintf(p, sz, "%zu", i); - if (x <= 0 || (size_t) x + 2 >= sz) + if (x < 0 || (size_t) x >= sz) return NULL; p += x; sz -= x; } if (j != 0) { + if (sz < 2) + return NULL; *p++ = mod->compat ? ',' : ':'; *p = '\0'; sz--; @@ -1346,11 +1348,13 @@ get_cell_header(struct lscpu_desc *desc, int col, for (i = desc->ncaches - 1; i >= 0; i--) { int x = snprintf(p, sz, "%s", desc->caches[i].name); - if (x <= 0 || (size_t) x + 2 > sz) + if (x < 0 || (size_t) x >= sz) return NULL; sz -= x; p += x; if (i > 0) { + if (sz < 2) + return NULL; *p++ = mod->compat ? ',' : ':'; *p = '\0'; sz--; diff --git a/sys-utils/mountpoint.c b/sys-utils/mountpoint.c index a43bfd6dd1..ad9c1da2e6 100644 --- a/sys-utils/mountpoint.c +++ b/sys-utils/mountpoint.c @@ -71,7 +71,7 @@ static int dir_to_device(struct mountpoint_control *ctl) len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : ctl->path); free(cn); - if (len < 0 || (size_t) len + 1 > sizeof(buf)) + if (len < 0 || (size_t) len >= sizeof(buf)) return -1; if (stat(buf, &pst) !=0) return -1; diff --git a/term-utils/agetty.c b/term-utils/agetty.c index d88cdc1c0c..55a00e125e 100644 --- a/term-utils/agetty.c +++ b/term-utils/agetty.c @@ -1001,8 +1001,8 @@ static void open_tty(char *tty, struct termios *tp, struct options *op) if ((gr = getgrnam("tty"))) gid = gr->gr_gid; - if (((len = snprintf(buf, sizeof(buf), "/dev/%s", tty)) >= - (int)sizeof(buf)) || (len < 0)) + len = snprintf(buf, sizeof(buf), "/dev/%s", tty); + if (len < 0 || (size_t)len >= sizeof(buf)) log_err(_("/dev/%s: cannot open as standard input: %m"), tty); /* Open the tty as standard input. */ diff --git a/term-utils/ttymsg.c b/term-utils/ttymsg.c index 18a723f867..2aab69f106 100644 --- a/term-utils/ttymsg.c +++ b/term-utils/ttymsg.c @@ -90,7 +90,7 @@ ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) { also wrong since people use /dev/pts/xxx. */ len = snprintf(device, sizeof(device), "%s%s", _PATH_DEV, line); - if (len < 0 || len + 1 > (ssize_t) sizeof(device)) { + if (len < 0 || (size_t)len >= sizeof(device)) { snprintf(errbuf, sizeof(errbuf), _("excessively long line arg")); return errbuf; } @@ -104,7 +104,7 @@ ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) { return NULL; len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device); - if (len < 0 || len + 1 > (ssize_t) sizeof(errbuf)) + if (len < 0 || (size_t)len >= sizeof(errbuf)) snprintf(errbuf, sizeof(errbuf), _("open failed")); return errbuf; } @@ -145,7 +145,7 @@ ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) { cpid = fork(); if (cpid < 0) { len = snprintf(errbuf, sizeof(errbuf), _("fork: %m")); - if (len < 0 || len + 1 > (ssize_t) sizeof(errbuf)) + if (len < 0 || (size_t)len >= sizeof(errbuf)) snprintf(errbuf, sizeof(errbuf), _("cannot fork")); close(fd); return errbuf; @@ -177,7 +177,7 @@ ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) { _exit(EXIT_FAILURE); len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device); - if (len < 0 || len + 1 > (ssize_t) sizeof(errbuf)) + if (len < 0 || (size_t)len >= sizeof(errbuf)) snprintf(errbuf, sizeof(errbuf), _("%s: BAD ERROR, message is " "far too long"), device); diff --git a/term-utils/wall.c b/term-utils/wall.c index 7d0dfe772d..1253d32cd7 100644 --- a/term-utils/wall.c +++ b/term-utils/wall.c @@ -217,8 +217,8 @@ static void buf_printf(struct buffer *bs, const char *fmt, ...) rc = vsnprintf(bs->data + bs->used, limit, fmt, ap); va_end(ap); - if (rc > 0 && (size_t) rc + 1 > limit) { /* not enoght, enlarge */ - buf_enlarge(bs, rc + 1); + if (rc >= 0 && (size_t) rc >= limit) { /* not enoght, enlarge */ + buf_enlarge(bs, (size_t)rc + 1); limit = bs->sz - bs->used; va_start(ap, fmt); rc = vsnprintf(bs->data + bs->used, limit, fmt, ap);;