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Groups > linux.kernel > #1271435
| From | Seth Forshee <seth.forshee@canonical.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v3 3/7] mtd: Check permissions towards mtd block device inode when mounting |
| Date | 2015-11-17 17:50 +0100 |
| Message-ID | <qvRCc-7wq-71@gated-at.bofh.it> (permalink) |
| References | <qvRC9-7wq-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Unprivileged users should not be able to mount mtd block devices
when they lack sufficient privileges towards the block device
inode. Update mount_mtd() to validate that the user has the
required access to the inode at the specified path. The check
will be skipped for CAP_SYS_ADMIN, so privileged mounts will
continue working as before.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
---
drivers/mtd/mtdsuper.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index b5b60e1af31c..5d7e7705fed8 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -125,6 +125,7 @@ struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
#ifdef CONFIG_BLOCK
struct block_device *bdev;
int ret, major;
+ int perm;
#endif
int mtdnr;
@@ -176,7 +177,10 @@ struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
/* try the old way - the hack where we allowed users to mount
* /dev/mtdblock$(n) but didn't actually _use_ the blockdev
*/
- bdev = lookup_bdev(dev_name, 0);
+ perm = MAY_READ;
+ if (!(flags & MS_RDONLY))
+ perm |= MAY_WRITE;
+ bdev = lookup_bdev(dev_name, perm);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
pr_debug("MTDSB: lookup_bdev() returned %d\n", ret);
--
1.9.1
--
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[PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 17:50 +0100
[PATCH v3 1/7] block_dev: Support checking inode permissions in lookup_bdev() Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 17:50 +0100
[PATCH v3 2/7] block_dev: Check permissions towards block device inode when mounting Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 17:50 +0100
[PATCH v3 3/7] mtd: Check permissions towards mtd block device inode when mounting Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 17:50 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-17 18:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 18:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates "Serge E. Hallyn" <serge@hallyn.com> - 2015-11-17 18:50 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-17 19:00 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 19:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard.weinberger@gmail.com> - 2015-11-17 20:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Octavian Purdila <octavian.purdila@intel.com> - 2015-11-17 20:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard@nod.at> - 2015-11-17 21:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Octavian Purdila <octavian.purdila@intel.com> - 2015-11-17 23:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-19 16:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Octavian Purdila <octavian.purdila@intel.com> - 2015-11-19 17:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-19 17:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates "Serge E. Hallyn" <serge.hallyn@ubuntu.com> - 2015-11-20 18:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard@nod.at> - 2015-11-17 20:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 20:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Theodore Ts'o <tytso@mit.edu> - 2015-11-18 20:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-18 20:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Serge Hallyn <serge.hallyn@ubuntu.com> - 2015-11-18 20:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-17 20:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 20:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-17 22:00 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 22:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-18 13:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-18 15:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-18 16:00 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-18 16:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-18 16:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard.weinberger@gmail.com> - 2015-11-18 16:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates James Morris <jmorris@namei.org> - 2015-11-19 08:50 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard@nod.at> - 2015-11-19 09:00 +0100
Re: [PATCH v3 0/7] User namespace mount updates "Serge E. Hallyn" <serge.hallyn@ubuntu.com> - 2015-11-19 15:30 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard@nod.at> - 2015-11-19 16:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Colin Walters <walters@verbum.org> - 2015-11-19 15:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Richard Weinberger <richard@nod.at> - 2015-11-19 15:50 +0100
Re: [PATCH v3 0/7] User namespace mount updates "Richard W.M. Jones" <rjones@redhat.com> - 2015-11-19 16:20 +0100
Re: [PATCH v3 0/7] User namespace mount updates "Serge E. Hallyn" <serge.hallyn@ubuntu.com> - 2015-11-19 16:00 +0100
Re: [PATCH v3 0/7] User namespace mount updates Nikolay Borisov <kernel@kyup.com> - 2015-11-18 16:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-18 16:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-17 20:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-17 21:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Al Viro <viro@ZenIV.linux.org.uk> - 2015-11-17 22:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-17 23:10 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-18 13:50 +0100
Re: [PATCH v3 0/7] User namespace mount updates Seth Forshee <seth.forshee@canonical.com> - 2015-11-18 15:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-18 16:40 +0100
Re: [PATCH v3 0/7] User namespace mount updates bfields@fieldses.org (J. Bruce Fields) - 2015-11-18 19:50 +0100
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