[PATCH v2] proc: fix /proc/*/map_files lookup some more
From: Alexey Dobriyan
Date: Sat Mar 03 2018 - 16:51:45 EST
I totally forgot that _parse_integer() accepts arbitrary amount of
leading zeroes leading to the following lookups:
OK
# readlink /proc/1/map_files/56427ecba000-56427eddc000
/lib/systemd/systemd
bogus
# readlink /proc/1/map_files/00000000000056427ecba000-56427eddc000
/lib/systemd/systemd
# readlink /proc/1/map_files/56427ecba000-00000000000056427eddc000
/lib/systemd/systemd
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
fs/proc/base.c | 4
tools/testing/selftests/proc/.gitignore | 4
tools/testing/selftests/proc/Makefile | 2
tools/testing/selftests/proc/proc-self-map-files-001.c | 82 ++++++++++++++++
tools/testing/selftests/proc/proc-self-map-files-002.c | 85 +++++++++++++++++
5 files changed, 176 insertions(+), 1 deletion(-)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1916,6 +1916,8 @@ static int dname_to_vma_addr(struct dentry *dentry,
unsigned long long sval, eval;
unsigned int len;
+ if (str[0] == '0' && str[1] != '-')
+ return -EINVAL;
len = _parse_integer(str, 16, &sval);
if (len & KSTRTOX_OVERFLOW)
return -EINVAL;
@@ -1927,6 +1929,8 @@ static int dname_to_vma_addr(struct dentry *dentry,
return -EINVAL;
str++;
+ if (str[0] == '0' && str[1])
+ return -EINVAL;
len = _parse_integer(str, 16, &eval);
if (len & KSTRTOX_OVERFLOW)
return -EINVAL;
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -1,2 +1,4 @@
-/proc-self-mem
+/proc-self-map-files-001
+/proc-self-map-files-002
/proc-self-syscall
+/proc-self-wchan
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -1,6 +1,8 @@
CFLAGS += -Wall -O2
TEST_GEN_PROGS :=
+TEST_GEN_PROGS += proc-self-map-files-001
+TEST_GEN_PROGS += proc-self-map-files-002
TEST_GEN_PROGS += proc-self-syscall
TEST_GEN_PROGS += proc-self-wchan
new file mode 100644
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-map-files-001.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@xxxxxxxxx>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Test readlink /proc/self/map_files/... */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+
+static void pass(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1)
+ exit(1);
+}
+
+static void fail(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
+ return;
+ exit(1);
+}
+
+int main(void)
+{
+ const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ void *p;
+ int fd;
+ unsigned long a, b;
+
+ fd = open("/dev/zero", O_RDONLY);
+ if (fd == -1)
+ return 1;
+
+ p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE, fd, 0);
+ if (p == MAP_FAILED)
+ return 1;
+
+ a = (unsigned long)p;
+ b = (unsigned long)p + PAGE_SIZE;
+
+ pass("/proc/self/map_files/%lx-%lx", a, b);
+ fail("/proc/self/map_files/ %lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx -%lx", a, b);
+ fail("/proc/self/map_files/%lx- %lx", a, b);
+ fail("/proc/self/map_files/%lx-%lx ", a, b);
+ fail("/proc/self/map_files/0%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-0%lx", a, b);
+ if (sizeof(long) == 4) {
+ fail("/proc/self/map_files/100000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-100000000%lx", a, b);
+ } else if (sizeof(long) == 8) {
+ fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
+ } else
+ return 1;
+
+ return 0;
+}
new file mode 100644
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-map-files-002.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@xxxxxxxxx>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Test readlink /proc/self/map_files/... with address 0. */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+
+static void pass(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1)
+ exit(1);
+}
+
+static void fail(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
+ return;
+ exit(1);
+}
+
+int main(void)
+{
+ const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ void *p;
+ int fd;
+ unsigned long a, b;
+
+ fd = open("/dev/zero", O_RDONLY);
+ if (fd == -1)
+ return 1;
+
+ p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+ if (p == MAP_FAILED) {
+ if (errno == EPERM)
+ return 2;
+ return 1;
+ }
+
+ a = (unsigned long)p;
+ b = (unsigned long)p + PAGE_SIZE;
+
+ pass("/proc/self/map_files/%lx-%lx", a, b);
+ fail("/proc/self/map_files/ %lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx -%lx", a, b);
+ fail("/proc/self/map_files/%lx- %lx", a, b);
+ fail("/proc/self/map_files/%lx-%lx ", a, b);
+ fail("/proc/self/map_files/0%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-0%lx", a, b);
+ if (sizeof(long) == 4) {
+ fail("/proc/self/map_files/100000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-100000000%lx", a, b);
+ } else if (sizeof(long) == 8) {
+ fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
+ } else
+ return 1;
+
+ return 0;
+}