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path: root/fs/fhandle.c
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2016-03-23fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn1-1/+1
This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-02vfs: read file_handle only once in handle_to_pathSasha Levin1-2/+3
We used to read file_handle twice. Once to get the amount of extra bytes, and once to fetch the entire structure. This may be problematic since we do size verifications only after the first read, so if the number of extra bytes changes in userspace between the first and second calls, we'll have an incoherent view of file_handle. Instead, read the constant size once, and copy that over to the final structure without having to re-read it again. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-21Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-1/+1
Pull nfsd update from Bruce Fields: "Included this time: - more nfsd containerization work from Stanislav Kinsbursky: we're not quite there yet, but should be by 3.9. - NFSv4.1 progress: implementation of basic backchannel security negotiation and the mandatory BACKCHANNEL_CTL operation. See http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues for remaining TODO's - Fixes for some bugs that could be triggered by unusual compounds. Our xdr code wasn't designed with v4 compounds in mind, and it shows. A more thorough rewrite is still a todo. - If you've ever seen "RPC: multiple fragments per record not supported" logged while using some sort of odd userland NFS client, that should now be fixed. - Further work from Jeff Layton on our mechanism for storing information about NFSv4 clients across reboots. - Further work from Bryan Schumaker on his fault-injection mechanism (which allows us to discard selective NFSv4 state, to excercise rarely-taken recovery code paths in the client.) - The usual mix of miscellaneous bugs and cleanup. Thanks to everyone who tested or contributed this cycle." * 'for-3.8' of git://linux-nfs.org/~bfields/linux: (111 commits) nfsd4: don't leave freed stateid hashed nfsd4: free_stateid can use the current stateid nfsd4: cleanup: replace rq_resused count by rq_next_page pointer nfsd: warn on odd reply state in nfsd_vfs_read nfsd4: fix oops on unusual readlike compound nfsd4: disable zero-copy on non-final read ops svcrpc: fix some printks NFSD: Correct the size calculation in fault_inject_write NFSD: Pass correct buffer size to rpc_ntop nfsd: pass proper net to nfsd_destroy() from NFSd kthreads nfsd: simplify service shutdown nfsd: replace boolean nfsd_up flag by users counter nfsd: simplify NFSv4 state init and shutdown nfsd: introduce helpers for generic resources init and shutdown nfsd: make NFSd service structure allocated per net nfsd: make NFSd service boot time per-net nfsd: per-net NFSd up flag introduced nfsd: move per-net startup code to separated function nfsd: pass net to __write_ports() and down nfsd: pass net to nfsd_set_nrthreads() ...
2012-11-19Fix misspellings of "whether" in comments.Adam Buchbinder1-2/+2
"Whether" is misspelled in various comments across the tree; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-08exportfs: add FILEID_INVALID to indicate invalid fid_typeNamjae Jeon1-1/+1
This commit adds FILEID_INVALID = 0xff in fid_type to indicate invalid fid_type It avoids using magic number 255 Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-09-27switch simple cases of fget_light to fdgetAl Viro1-10/+7
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-07vfs: prefer ->dentry->d_sb to ->mnt->mnt_sbAl Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-04vfs: mnt_id/mnt_group_id movedAl Viro1-1/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-04-15fs/fhandle.c: add <linux/personality.h> for ia64Jeff Mahoney1-0/+1
force_o_largefile() on ia64 is defined in <asm/fcntl.h> and requires <linux/personality.h>. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15vfs: Add open by file handle supportAneesh Kumar K.V1-0/+158
[AV: duplicate of open() guts removed; file_open_root() used instead] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15vfs: Add name to file handle conversion supportAneesh Kumar K.V1-0/+107
The syscall also return mount id which can be used to lookup file system specific information such as uuid in /proc/<pid>/mountinfo Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>