From: Seth Forshee <seth.forshee@canonical.com> To: "Eric W. Biederman" <ebiederm@xmission.com>, Alexander Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@canonical.com>, Seth Forshee <seth.forshee@canonical.com>, dm-devel@redhat.com, Miklos Szeredi <miklos@szeredi.hu>, Richard Weinberger <richard.weinberger@gmail.com>, linux-security-module@vger.kernel.org, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, fuse-devel@lists.sourceforge.net, Austin S Hemmelgarn <ahferroin7@gmail.com>, linux-mtd@lists.infradead.org, selinux@tycho.nsa.gov, linux-fsdevel@vger.kernel.org Subject: [PATCH 02/19] block_dev: Check permissions towards block device inode when mounting Date: Wed, 2 Dec 2015 09:40:02 -0600 [thread overview] Message-ID: <1449070821-73820-3-git-send-email-seth.forshee@canonical.com> (raw) In-Reply-To: <1449070821-73820-1-git-send-email-seth.forshee@canonical.com> Unprivileged users should not be able to mount block devices when they lack sufficient privileges towards the block device inode. Update blkdev_get_by_path() 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> --- fs/block_dev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 3ebbde85d898..4fdb6ab59816 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1424,9 +1424,14 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, void *holder) { struct block_device *bdev; + int perm = 0; int err; - bdev = lookup_bdev(path, 0); + if (mode & FMODE_READ) + perm |= MAY_READ; + if (mode & FMODE_WRITE) + perm |= MAY_WRITE; + bdev = lookup_bdev(path, perm); if (IS_ERR(bdev)) return bdev; -- 1.9.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
WARNING: multiple messages have this Message-ID (diff)
From: Seth Forshee <seth.forshee@canonical.com> To: "Eric W. Biederman" <ebiederm@xmission.com>, Alexander Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@canonical.com>, Richard Weinberger <richard.weinberger@gmail.com>, Austin S Hemmelgarn <ahferroin7@gmail.com>, Miklos Szeredi <miklos@szeredi.hu>, linux-bcache@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, Seth Forshee <seth.forshee@canonical.com> Subject: [PATCH 02/19] block_dev: Check permissions towards block device inode when mounting Date: Wed, 2 Dec 2015 09:40:02 -0600 [thread overview] Message-ID: <1449070821-73820-3-git-send-email-seth.forshee@canonical.com> (raw) In-Reply-To: <1449070821-73820-1-git-send-email-seth.forshee@canonical.com> Unprivileged users should not be able to mount block devices when they lack sufficient privileges towards the block device inode. Update blkdev_get_by_path() 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> --- fs/block_dev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 3ebbde85d898..4fdb6ab59816 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1424,9 +1424,14 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, void *holder) { struct block_device *bdev; + int perm = 0; int err; - bdev = lookup_bdev(path, 0); + if (mode & FMODE_READ) + perm |= MAY_READ; + if (mode & FMODE_WRITE) + perm |= MAY_WRITE; + bdev = lookup_bdev(path, perm); if (IS_ERR(bdev)) return bdev; -- 1.9.1
next prev parent reply other threads:[~2015-12-02 15:40 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-12-02 15:40 [PATCH 00/19] Support fuse mounts in user namespaces Seth Forshee 2015-12-02 15:40 ` Seth Forshee [this message] 2015-12-02 15:40 ` [PATCH 02/19] block_dev: Check permissions towards block device inode when mounting Seth Forshee 2015-12-04 16:28 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 03/19] fs: Treat foreign mounts as nosuid Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 16:55 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 04/19] selinux: Add support for unprivileged mounts from user namespaces Seth Forshee 2015-12-02 15:40 ` [PATCH 05/19] userns: Replace in_userns with current_in_userns Seth Forshee 2015-12-04 17:01 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 08/19] cred: Reject inodes with invalid ids in set_create_file_as() Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 16:49 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 12/19] fs: Don't remove suid for CAP_FSETID in s_user_ns Seth Forshee 2015-12-04 19:02 ` Serge E. Hallyn [not found] ` <1449070821-73820-1-git-send-email-seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> 2015-12-02 15:40 ` [PATCH 01/19] block_dev: Support checking inode permissions in lookup_bdev() Seth Forshee 2015-12-02 15:40 ` Seth Forshee [not found] ` <1449070821-73820-2-git-send-email-seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> 2015-12-04 16:26 ` Serge E. Hallyn 2015-12-04 16:26 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 06/19] Smack: Handle labels consistently in untrusted mounts Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-02 15:40 ` [PATCH 07/19] fs: Check for invalid i_uid in may_follow_link() Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 16:42 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 09/19] fs: Refuse uid/gid changes which don't map into s_user_ns Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 17:27 ` Serge E. Hallyn 2015-12-04 17:46 ` Seth Forshee 2015-12-04 19:42 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 10/19] fs: Update posix_acl support to handle user namespace mounts Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 18:50 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 11/19] fs: Ensure the mounter of a filesystem is privileged towards its inodes Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 19:00 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 13/19] fs: Allow superblock owner to access do_remount_sb() Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 19:02 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 14/19] fs: Permit FIBMAP for users with CAP_SYS_RAWIO in s_user_ns Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 19:11 ` Serge E. Hallyn 2015-12-04 20:05 ` Theodore Ts'o 2015-12-04 20:07 ` Serge E. Hallyn [not found] ` <20151204200736.GJ3624-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org> 2015-12-04 20:45 ` Seth Forshee 2015-12-04 20:45 ` Seth Forshee 2015-12-04 23:11 ` Theodore Ts'o 2015-12-04 23:43 ` Serge E. Hallyn 2015-12-05 6:15 ` Seth Forshee 2015-12-05 0:00 ` Andreas Dilger 2015-12-02 15:40 ` [PATCH 17/19] fuse: Support fuse filesystems outside of init_user_ns Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 15:38 ` Seth Forshee 2015-12-04 20:03 ` Serge E. Hallyn 2015-12-04 20:41 ` Seth Forshee 2015-12-04 21:57 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 18/19] fuse: Restrict allow_other to the superblock's namespace or a descendant Seth Forshee 2015-12-02 15:40 ` Seth Forshee 2015-12-04 20:05 ` Serge E. Hallyn 2015-12-04 20:43 ` Seth Forshee 2015-12-04 21:57 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 15/19] capabilities: Allow privileged user in s_user_ns to set file caps Seth Forshee 2015-12-04 19:42 ` Serge E. Hallyn 2015-12-04 20:36 ` Seth Forshee 2015-12-04 22:05 ` Serge E. Hallyn 2015-12-02 15:40 ` [PATCH 16/19] fuse: Add support for pid namespaces Seth Forshee 2015-12-02 15:40 ` [PATCH 19/19] fuse: Allow user namespace mounts Seth Forshee
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