When /etc/mtab is a symlink of /proc/mounts, mke2fs without -FF option
can create a filesystem on the image file that is mounted.
According to mke2fs man page, we should specify -FF option in this case.
This patch protects filesystem from unintended mke2fs caused by human error.
How to reproduce:
# mke2fs -t ext4 -Fq fs.img
# mount -o loop fs.img /mnt/mp1
# mke2fs -t ext4 -Fq fs.img && echo "mke2fs success"
mke2fs success
Signed-off-by: Kazuya Mio <[email protected]>
---
configure.in | 1 +
lib/ext2fs/ismounted.c | 41 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+)
diff --git a/configure.in b/configure.in
index 049dc11..fef8d9b 100644
--- a/configure.in
+++ b/configure.in
@@ -920,6 +920,7 @@ AC_CHECK_HEADERS(m4_flatten([
linux/falloc.h
linux/fd.h
linux/major.h
+ linux/loop.h
net/if_dl.h
netinet/in.h
sys/disklabel.h
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
index 2c1bd75..6c6ecff 100644
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -21,6 +21,13 @@
#ifdef HAVE_LINUX_FD_H
#include <linux/fd.h>
#endif
+#ifdef HAVE_LINUX_LOOP_H
+#include <linux/loop.h>
+#include <sys/ioctl.h>
+#ifdef HAVE_LINUX_MAJOR_H
+#include <linux/major.h>
+#endif /* HAVE_LINUX_MAJOR_H */
+#endif /* HAVE_LINUX_LOOP_H */
#ifdef HAVE_MNTENT_H
#include <mntent.h>
#endif
@@ -35,6 +42,36 @@
#include "ext2_fs.h"
#include "ext2fs.h"
+/*
+ * Check to see if a regular file is mounted.
+ * If /etc/mtab/ is a symlink of /proc/mounts, you will need the following check
+ * because the name in /proc/mounts is a loopback device not a regular file.
+ */
+static int check_loop_mounted(const char *mnt_fsname, dev_t mnt_rdev,
+ dev_t file_dev, ino_t file_ino)
+{
+#if defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H)
+ struct loop_info64 loopinfo;
+ int loop_fd, ret;
+
+ if (major(mnt_rdev) == LOOP_MAJOR) {
+ loop_fd = open(mnt_fsname, O_RDONLY);
+ if (loop_fd < 0)
+ return -1;
+
+ ret = ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo);
+ close(loop_fd);
+ if (ret < 0)
+ return -1;
+
+ if (file_dev == loopinfo.lo_device &&
+ file_ino == loopinfo.lo_inode)
+ return 1;
+ }
+#endif /* defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H) */
+ return 0;
+}
+
#ifdef HAVE_SETMNTENT
/*
* Helper function which checks a file in /etc/mtab format to see if a
@@ -82,6 +119,10 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
#ifndef __GNU__
if (file_rdev && (file_rdev == st_buf.st_rdev))
break;
+ if (check_loop_mounted(mnt->mnt_fsname,
+ st_buf.st_rdev, file_dev,
+ file_ino) == 1)
+ break;
#endif /* __GNU__ */
} else {
if (file_dev && ((file_dev == st_buf.st_dev) &&
Ping?
Any comments/suggestions will be welcome.
Regards,
Kazuya Mio
> 2013/11/07 15:18:05, [email protected] wrote:
>
> When /etc/mtab is a symlink of /proc/mounts, mke2fs without -FF option
> can create a filesystem on the image file that is mounted.
> According to mke2fs man page, we should specify -FF option in this case.
>
> This patch protects filesystem from unintended mke2fs caused by human error.
>
> How to reproduce:
> # mke2fs -t ext4 -Fq fs.img
> # mount -o loop fs.img /mnt/mp1
> # mke2fs -t ext4 -Fq fs.img && echo "mke2fs success"
> mke2fs success
>
> Signed-off-by: Kazuya Mio <[email protected]>
> ---
> configure.in | 1 +
> lib/ext2fs/ismounted.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 42 insertions(+)
> diff --git a/configure.in b/configure.in
> index 049dc11..fef8d9b 100644
> --- a/configure.in
> +++ b/configure.in
> @@ -920,6 +920,7 @@ AC_CHECK_HEADERS(m4_flatten([
> linux/falloc.h
> linux/fd.h
> linux/major.h
> + linux/loop.h
> net/if_dl.h
> netinet/in.h
> sys/disklabel.h
> diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
> index 2c1bd75..6c6ecff 100644
> --- a/lib/ext2fs/ismounted.c
> +++ b/lib/ext2fs/ismounted.c
> @@ -21,6 +21,13 @@
> #ifdef HAVE_LINUX_FD_H
> #include <linux/fd.h>
> #endif
> +#ifdef HAVE_LINUX_LOOP_H
> +#include <linux/loop.h>
> +#include <sys/ioctl.h>
> +#ifdef HAVE_LINUX_MAJOR_H
> +#include <linux/major.h>
> +#endif /* HAVE_LINUX_MAJOR_H */
> +#endif /* HAVE_LINUX_LOOP_H */
> #ifdef HAVE_MNTENT_H
> #include <mntent.h>
> #endif
> @@ -35,6 +42,36 @@
> #include "ext2_fs.h"
> #include "ext2fs.h"
>
> +/*
> + * Check to see if a regular file is mounted.
> + * If /etc/mtab/ is a symlink of /proc/mounts, you will need the following check
> + * because the name in /proc/mounts is a loopback device not a regular file.
> + */
> +static int check_loop_mounted(const char *mnt_fsname, dev_t mnt_rdev,
> + dev_t file_dev, ino_t file_ino)
> +{
> +#if defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H)
> + struct loop_info64 loopinfo;
> + int loop_fd, ret;
> +
> + if (major(mnt_rdev) == LOOP_MAJOR) {
> + loop_fd = open(mnt_fsname, O_RDONLY);
> + if (loop_fd < 0)
> + return -1;
> +
> + ret = ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo);
> + close(loop_fd);
> + if (ret < 0)
> + return -1;
> +
> + if (file_dev == loopinfo.lo_device &&
> + file_ino == loopinfo.lo_inode)
> + return 1;
> + }
> +#endif /* defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H) */
> + return 0;
> +}
> +
> #ifdef HAVE_SETMNTENT
> /*
> * Helper function which checks a file in /etc/mtab format to see if a
> @@ -82,6 +119,10 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
> #ifndef __GNU__
> if (file_rdev && (file_rdev == st_buf.st_rdev))
> break;
> + if (check_loop_mounted(mnt->mnt_fsname,
> + st_buf.st_rdev, file_dev,
> + file_ino) == 1)
> + break;
> #endif /* __GNU__ */
> } else {
> if (file_dev && ((file_dev == st_buf.st_dev) &&
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 29, 2013 at 03:25:31PM +0900, Kazuya Mio wrote:
> Ping?
> Any comments/suggestions will be welcome.
I /think/ it looks fine...
--D
>
> Regards,
> Kazuya Mio
>
> > 2013/11/07 15:18:05, [email protected] wrote:
> >
> > When /etc/mtab is a symlink of /proc/mounts, mke2fs without -FF option
> > can create a filesystem on the image file that is mounted.
> > According to mke2fs man page, we should specify -FF option in this case.
> >
> > This patch protects filesystem from unintended mke2fs caused by human error.
> >
> > How to reproduce:
> > # mke2fs -t ext4 -Fq fs.img
> > # mount -o loop fs.img /mnt/mp1
> > # mke2fs -t ext4 -Fq fs.img && echo "mke2fs success"
> > mke2fs success
> >
> > Signed-off-by: Kazuya Mio <[email protected]>
> > ---
> > configure.in | 1 +
> > lib/ext2fs/ismounted.c | 41 +++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 42 insertions(+)
> > diff --git a/configure.in b/configure.in
> > index 049dc11..fef8d9b 100644
> > --- a/configure.in
> > +++ b/configure.in
> > @@ -920,6 +920,7 @@ AC_CHECK_HEADERS(m4_flatten([
> > linux/falloc.h
> > linux/fd.h
> > linux/major.h
> > + linux/loop.h
> > net/if_dl.h
> > netinet/in.h
> > sys/disklabel.h
> > diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
> > index 2c1bd75..6c6ecff 100644
> > --- a/lib/ext2fs/ismounted.c
> > +++ b/lib/ext2fs/ismounted.c
> > @@ -21,6 +21,13 @@
> > #ifdef HAVE_LINUX_FD_H
> > #include <linux/fd.h>
> > #endif
> > +#ifdef HAVE_LINUX_LOOP_H
> > +#include <linux/loop.h>
> > +#include <sys/ioctl.h>
> > +#ifdef HAVE_LINUX_MAJOR_H
> > +#include <linux/major.h>
> > +#endif /* HAVE_LINUX_MAJOR_H */
> > +#endif /* HAVE_LINUX_LOOP_H */
> > #ifdef HAVE_MNTENT_H
> > #include <mntent.h>
> > #endif
> > @@ -35,6 +42,36 @@
> > #include "ext2_fs.h"
> > #include "ext2fs.h"
> >
> > +/*
> > + * Check to see if a regular file is mounted.
> > + * If /etc/mtab/ is a symlink of /proc/mounts, you will need the following check
> > + * because the name in /proc/mounts is a loopback device not a regular file.
> > + */
> > +static int check_loop_mounted(const char *mnt_fsname, dev_t mnt_rdev,
> > + dev_t file_dev, ino_t file_ino)
> > +{
> > +#if defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H)
> > + struct loop_info64 loopinfo;
> > + int loop_fd, ret;
> > +
> > + if (major(mnt_rdev) == LOOP_MAJOR) {
> > + loop_fd = open(mnt_fsname, O_RDONLY);
> > + if (loop_fd < 0)
> > + return -1;
> > +
> > + ret = ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo);
> > + close(loop_fd);
> > + if (ret < 0)
> > + return -1;
> > +
> > + if (file_dev == loopinfo.lo_device &&
> > + file_ino == loopinfo.lo_inode)
> > + return 1;
> > + }
> > +#endif /* defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H) */
> > + return 0;
> > +}
> > +
> > #ifdef HAVE_SETMNTENT
> > /*
> > * Helper function which checks a file in /etc/mtab format to see if a
> > @@ -82,6 +119,10 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
> > #ifndef __GNU__
> > if (file_rdev && (file_rdev == st_buf.st_rdev))
> > break;
> > + if (check_loop_mounted(mnt->mnt_fsname,
> > + st_buf.st_rdev, file_dev,
> > + file_ino) == 1)
> > + break;
> > #endif /* __GNU__ */
> > } else {
> > if (file_dev && ((file_dev == st_buf.st_dev) &&
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 07, 2013 at 03:18:05PM +0900, Kazuya Mio wrote:
> When /etc/mtab is a symlink of /proc/mounts, mke2fs without -FF option
> can create a filesystem on the image file that is mounted.
> According to mke2fs man page, we should specify -FF option in this case.
>
> This patch protects filesystem from unintended mke2fs caused by human error.
>
> How to reproduce:
> # mke2fs -t ext4 -Fq fs.img
> # mount -o loop fs.img /mnt/mp1
> # mke2fs -t ext4 -Fq fs.img && echo "mke2fs success"
> mke2fs success
>
> Signed-off-by: Kazuya Mio <[email protected]>
Thanks, applied.
- Ted