Commit 35318db5 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds
Browse files

proc: fix /proc/*/map_files lookup some more 

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

Link: http://lkml.kernel.org/r/20180303215130.GA23480@avx2


Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: default avatarCyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b4884f23

fs/proc/base.c

+4 −0
Original line number Diff line number Diff line
@@ -1913,6 +1913,8 @@ 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;
@@ -1924,6 +1926,8 @@ 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;

tools/testing/selftests/proc/.gitignore

+3 −1
Original line number Diff line number Diff line 
/proc-self-mem

/proc-self-map-files-001

/proc-self-map-files-002

/proc-self-syscall

/proc-self-wchan

tools/testing/selftests/proc/Makefile

+2 −0
Original line number Diff line number Diff line 
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

tools/testing/selftests/proc/proc-self-map-files-001.c

0 → 100644
+82 −0
Original line number Diff line number Diff line 
/*

 * Copyright _ 2018 Alexey Dobriyan <adobriyan@gmail.com>

 *

 * 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;

}

tools/testing/selftests/proc/proc-self-map-files-002.c

0 → 100644
+85 −0
Original line number Diff line number Diff line 
/*

 * Copyright _ 2018 Alexey Dobriyan <adobriyan@gmail.com>

 *

 * 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;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE