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2016-05-17fs/cifs: correctly to anonymous authentication for the NTLM(v1) authenticationStefan Metzmacher
Only server which map unknown users to guest will allow access using a non-null NTChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <smfrench@gmail.com>
2016-05-17fs/cifs: correctly to anonymous authentication for the LANMAN authenticationStefan Metzmacher
Only server which map unknown users to guest will allow access using a non-null LMChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <smfrench@gmail.com>
2016-05-17fs/cifs: correctly to anonymous authentication via NTLMSSPStefan Metzmacher
See [MS-NLMP] 3.2.5.1.2 Server Receives an AUTHENTICATE_MESSAGE from the Client: ... Set NullSession to FALSE If (AUTHENTICATE_MESSAGE.UserNameLen == 0 AND AUTHENTICATE_MESSAGE.NtChallengeResponse.Length == 0 AND (AUTHENTICATE_MESSAGE.LmChallengeResponse == Z(1) OR AUTHENTICATE_MESSAGE.LmChallengeResponse.Length == 0)) -- Special case: client requested anonymous authentication Set NullSession to TRUE ... Only server which map unknown users to guest will allow access using a non-null NTChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 CC: Stable <stable@vger.kernel.org> Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2016-05-17cifs: remove any preceding delimiter from prefix_pathSachin Prabhu
We currently do not check if any delimiter exists before the prefix path in cifs_compose_mount_options(). Consequently when building the devname using cifs_build_devname() we can end up with multiple delimiters separating the UNC and the prefix path. An issue was reported by the customer mounting a folder within a DFS share from a Netapp server which uses McAfee antivirus. We have narrowed down the cause to the use of double backslashes in the file name used to open the file. This was determined to be caused because of additional delimiters as a result of the bug. In addition to changes in cifs_build_devname(), we also fix cifs_parse_devname() to ignore any preceding delimiter for the prefix path. The problem was originally reported on RHEL 6 in RHEL bz 1252721. This is the upstream version of the fix. The fix was confirmed by looking at the packet capture of a DFS mount. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2016-05-17cifs: Use file_dentry()Goldwyn Rodrigues
CIFS may be used as lower layer of overlayfs and accessing f_path.dentry can lead to a crash. Fix by replacing direct access of file->f_path.dentry with the file_dentry() accessor, which will always return a native object. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
2016-05-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull parallel filesystem directory handling update from Al Viro. This is the main parallel directory work by Al that makes the vfs layer able to do lookup and readdir in parallel within a single directory. That's a big change, since this used to be all protected by the directory inode mutex. The inode mutex is replaced by an rwsem, and serialization of lookups of a single name is done by a "in-progress" dentry marker. The series begins with xattr cleanups, and then ends with switching filesystems over to actually doing the readdir in parallel (switching to the "iterate_shared()" that only takes the read lock). A more detailed explanation of the process from Al Viro: "The xattr work starts with some acl fixes, then switches ->getxattr to passing inode and dentry separately. This is the point where the things start to get tricky - that got merged into the very beginning of the -rc3-based #work.lookups, to allow untangling the security_d_instantiate() mess. The xattr work itself proceeds to switch a lot of filesystems to generic_...xattr(); no complications there. After that initial xattr work, the series then does the following: - untangle security_d_instantiate() - convert a bunch of open-coded lookup_one_len_unlocked() to calls of that thing; one such place (in overlayfs) actually yields a trivial conflict with overlayfs fixes later in the cycle - overlayfs ended up switching to a variant of lookup_one_len_unlocked() sans the permission checks. I would've dropped that commit (it gets overridden on merge from #ovl-fixes in #for-next; proper resolution is to use the variant in mainline fs/overlayfs/super.c), but I didn't want to rebase the damn thing - it was fairly late in the cycle... - some filesystems had managed to depend on lookup/lookup exclusion for *fs-internal* data structures in a way that would break if we relaxed the VFS exclusion. Fixing hadn't been hard, fortunately. - core of that series - parallel lookup machinery, replacing ->i_mutex with rwsem, making lookup_slow() take it only shared. At that point lookups happen in parallel; lookups on the same name wait for the in-progress one to be done with that dentry. Surprisingly little code, at that - almost all of it is in fs/dcache.c, with fs/namei.c changes limited to lookup_slow() - making it use the new primitive and actually switching to locking shared. - parallel readdir stuff - first of all, we provide the exclusion on per-struct file basis, same as we do for read() vs lseek() for regular files. That takes care of most of the needed exclusion in readdir/readdir; however, these guys are trickier than lookups, so I went for switching them one-by-one. To do that, a new method '->iterate_shared()' is added and filesystems are switched to it as they are either confirmed to be OK with shared lock on directory or fixed to be OK with that. I hope to kill the original method come next cycle (almost all in-tree filesystems are switched already), but it's still not quite finished. - several filesystems get switched to parallel readdir. The interesting part here is dealing with dcache preseeding by readdir; that needs minor adjustment to be safe with directory locked only shared. Most of the filesystems doing that got switched to in those commits. Important exception: NFS. Turns out that NFS folks, with their, er, insistence on VFS getting the fuck out of the way of the Smart Filesystem Code That Knows How And What To Lock(tm) have grown the locking of their own. They had their own homegrown rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink is the reader there). Of course, with VFS getting the fuck out of the way, as requested, the actual smarts of the smart filesystem code etc. had become exposed... - do_last/lookup_open/atomic_open cleanups. As the result, open() without O_CREAT locks the directory only shared. Including the ->atomic_open() case. Backmerge from #for-linus in the middle of that - atomic_open() fix got brought in. - then comes NFS switch to saner (VFS-based ;-) locking, killing the homegrown "lookup and readdir are writers" kinda-sorta rwsem. All exclusion for sillyunlink/lookup is done by the parallel lookups mechanism. Exclusion between sillyunlink and rmdir is a real rwsem now - rmdir being the writer. Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel now. - the rest of the series consists of switching a lot of filesystems to parallel readdir; in a lot of cases ->llseek() gets simplified as well. One backmerge in there (again, #for-linus - rockridge fix)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits) ext4: switch to ->iterate_shared() hfs: switch to ->iterate_shared() hfsplus: switch to ->iterate_shared() hostfs: switch to ->iterate_shared() hpfs: switch to ->iterate_shared() hpfs: handle allocation failures in hpfs_add_pos() gfs2: switch to ->iterate_shared() f2fs: switch to ->iterate_shared() afs: switch to ->iterate_shared() befs: switch to ->iterate_shared() befs: constify stuff a bit isofs: switch to ->iterate_shared() get_acorn_filename(): deobfuscate a bit btrfs: switch to ->iterate_shared() logfs: no need to lock directory in lseek switch ecryptfs to ->iterate_shared 9p: switch to ->iterate_shared() fat: switch to ->iterate_shared() romfs, squashfs: switch to ->iterate_shared() more trivial ->iterate_shared conversions ...
2016-05-17Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "API: - Crypto self tests can now be disabled at boot/run time. - Add async support to algif_aead. Algorithms: - A large number of fixes to MPI from Nicolai Stange. - Performance improvement for HMAC DRBG. Drivers: - Use generic crypto engine in omap-des. - Merge ppc4xx-rng and crypto4xx drivers. - Fix lockups in sun4i-ss driver by disabling IRQs. - Add DMA engine support to ccp. - Reenable talitos hash algorithms. - Add support for Hisilicon SoC RNG. - Add basic crypto driver for the MXC SCC. Others: - Do not allocate crypto hash tfm in NORECLAIM context in ecryptfs" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (77 commits) crypto: qat - change the adf_ctl_stop_devices to void crypto: caam - fix caam_jr_alloc() ret code crypto: vmx - comply with ABIs that specify vrsave as reserved. crypto: testmgr - Add a flag allowing the self-tests to be disabled at runtime. crypto: ccp - constify ccp_actions structure crypto: marvell/cesa - Use dma_pool_zalloc crypto: qat - make adf_vf_isr.c dependant on IOV config crypto: qat - Fix typo in comments lib: asn1_decoder - add MODULE_LICENSE("GPL") crypto: omap-sham - Use dma_request_chan() for requesting DMA channel crypto: omap-des - Use dma_request_chan() for requesting DMA channel crypto: omap-aes - Use dma_request_chan() for requesting DMA channel crypto: omap-des - Integrate with the crypto engine framework crypto: s5p-sss - fix incorrect usage of scatterlists api crypto: s5p-sss - Fix missed interrupts when working with 8 kB blocks crypto: s5p-sss - Use common BIT macro crypto: mxc-scc - fix unwinding in mxc_scc_crypto_register() crypto: mxc-scc - signedness bugs in mxc_scc_ablkcipher_req_init() crypto: talitos - fix ahash algorithms registration crypto: ccp - Ensure all dependencies are specified ...
2016-05-17Merge branch 'ovl-fixes' into for-linusAl Viro
Backmerge to resolve a conflict in ovl_lookup_real(); "ovl_lookup_real(): use lookup_one_len_unlocked()" instead, but it was too late in the cycle to rebase.
2016-05-16Merge branch 'efi-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes in this cycle were: - Drop the unused EFI_SYSTEM_TABLES efi.flags bit and ensure the ARM/arm64 EFI System Table mapping is read-only (Ard Biesheuvel) - Add a comment to explain that one of the code paths in the x86/pat code is only executed for EFI boot (Matt Fleming) - Improve Secure Boot status checks on arm64 and handle unexpected errors (Linn Crosetto) - Remove the global EFI memory map variable 'memmap' as the same information is already available in efi::memmap (Matt Fleming) - Add EFI Memory Attribute table support for ARM/arm64 (Ard Biesheuvel) - Add EFI GOP framebuffer support for ARM/arm64 (Ard Biesheuvel) - Add EFI Bootloader Control driver for storing reboot(2) data in EFI variables for consumption by bootloaders (Jeremy Compostella) - Add Core EFI capsule support (Matt Fleming) - Add EFI capsule char driver (Kweh, Hock Leong) - Unify EFI memory map code for ARM and arm64 (Ard Biesheuvel) - Add generic EFI support for detecting when firmware corrupts CPU status register bits (like IRQ flags) when performing EFI runtime service calls (Mark Rutland) ... and other misc cleanups" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) efivarfs: Make efivarfs_file_ioctl() static efi: Merge boolean flag arguments efi/capsule: Move 'capsule' to the stack in efi_capsule_supported() efibc: Fix excessive stack footprint warning efi/capsule: Make efi_capsule_pending() lockless efi: Remove unnecessary (and buggy) .memmap initialization from the Xen EFI driver efi/runtime-wrappers: Remove ARCH_EFI_IRQ_FLAGS_MASK #ifdef x86/efi: Enable runtime call flag checking arm/efi: Enable runtime call flag checking arm64/efi: Enable runtime call flag checking efi/runtime-wrappers: Detect firmware IRQ flag corruption efi/runtime-wrappers: Remove redundant #ifdefs x86/efi: Move to generic {__,}efi_call_virt() arm/efi: Move to generic {__,}efi_call_virt() arm64/efi: Move to generic {__,}efi_call_virt() efi/runtime-wrappers: Add {__,}efi_call_virt() templates efi/arm-init: Reserve rather than unmap the memory map for ARM as well efi: Add misc char driver interface to update EFI firmware x86/efi: Force EFI reboot to process pending capsules efi: Add 'capsule' update support ...
2016-05-16namei: Improve hash mixing if CONFIG_DCACHE_WORD_ACCESSGeorge Spelvin
The hash mixing between adding the next 64 bits of name was just a bit weak. Replaced with a still very fast but slightly more effective mixing function. Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Overlayfs fixes from Miklos, assorted fixes from me. Stable fodder of varying severity, all sat in -next for a while" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ovl: ignore permissions on underlying lookup vfs: add lookup_hash() helper vfs: rename: check backing inode being equal vfs: add vfs_select_inode() helper get_rock_ridge_filename(): handle malformed NM entries ecryptfs: fix handling of directory opening atomic_open(): fix the handling of create_error fix the copy vs. map logics in blk_rq_map_user_iov() do_splice_to(): cap the size before passing to ->splice_read()
2016-05-13Merge branch 'for-4.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "During v4.6-rc1 cgroup namespace support was merged. There is an issue where it's impossible to tell whether a given cgroup mount point is bind mounted or namespaced. Serge has been working on the issue but it took longer than expected to resolve, so the late pull request. Given that it's a completely new feature and the patches don't touch anything else, the risk seems acceptable. However, if this is too late, an alternative is plugging new cgroup ns creation for v4.6 and retrying for v4.7" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix compile warning kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces kernfs_path_from_node_locked: don't overwrite nlen
2016-05-13ext4: switch to ->iterate_shared()Al Viro
Note that we need relax_dir() equivalent for directories locked shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-13hfs: switch to ->iterate_shared()Al Viro
exact parallel of hfsplus analogue Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-13hfsplus: switch to ->iterate_shared()Al Viro
We need to protect the list of hfsplus_readdir_data against parallel insertions (in readdir) and removals (in release). Add a spinlock for that. Note that it has nothing to do with protection of hfsplus_readdir_data->key - we have an exclusion between hfsplus_readdir() and hfsplus_delete_cat() on directory lock and between several hfsplus_readdir() for the same struct file on ->f_pos_lock. The spinlock is strictly for list changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12hostfs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12hpfs: switch to ->iterate_shared()Al Viro
NOTE: the only reason we can do that without ->i_rdir_offs races is that hpfs_lock() serializes everything in there anyway. It's not that hard to get rid of, but not as part of this series... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12hpfs: handle allocation failures in hpfs_add_pos()Al Viro
pr_err() is nice, but we'd better propagate the error to caller and not proceed to violate the invariants (namely, "every file with f_pos tied to directory block should have its address visible in per-inode array"). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12ocfs2: fix posix_acl_create deadlockJunxiao Bi
Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") refactored code to use posix_acl_create. The problem with this function is that it is not mindful of the cluster wide inode lock making it unsuitable for use with ocfs2 inode creation with ACLs. For example, when used in ocfs2_mknod, this function can cause deadlock as follows. The parent dir inode lock is taken when calling posix_acl_create -> get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can cause deadlock if there is a blocked remote lock request waiting for the lock to be downconverted. And same deadlock happened in ocfs2_reflink. This fix is to revert back using ocfs2_init_acl. Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-12ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hangJunxiao Bi
Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") introduced this issue. ocfs2_setattr called by chmod command holds cluster wide inode lock when calling posix_acl_chmod. This latter function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These two are also called directly from vfs layer for getfacl/setfacl commands and therefore acquire the cluster wide inode lock. If a remote conversion request comes after the first inode lock in ocfs2_setattr, OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to inode lock from the ocfs2_iop_get_acl() to block indefinetly. The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which does not call back into the filesystem. Therefore, we restore ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that instead. Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-12gfs2: switch to ->iterate_shared()Al Viro
protected by glock and already used without locking the directory by gfs2_get_name() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry callSerge E. Hallyn
Our caller expects 0 on success, not >0. This fixes a bug in the patch cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces where /sys does not show up in mountinfo, breaking criu. Thanks for catching this, Andrei. Reported-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-11Merge branch 'ovl-fixes' into for-linusAl Viro
2016-05-11ovl: ignore permissions on underlying lookupMiklos Szeredi
Generally permission checking is not necessary when overlayfs looks up a dentry on one of the underlying layers, since search permission on base directory was already checked in ovl_permission(). More specifically using lookup_one_len() causes a problem when the lower directory lacks search permission for a specific user while the upper directory does have search permission. Since lookups are cached, this causes inconsistency in behavior: success depends on who did the first lookup. So instead use lookup_hash() which doesn't do the permission check. Reported-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-11vfs: add lookup_hash() helperMiklos Szeredi
Overlayfs needs lookup without inode_permission() and already has the name hash (in form of dentry->d_name on overlayfs dentry). It also doesn't support filesystems with d_op->d_hash() so basically it only needs the actual hashed lookup from lookup_one_len_unlocked() So add a new helper that does unlocked lookup of a hashed name. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-11vfs: rename: check backing inode being equalMiklos Szeredi
If a file is renamed to a hardlink of itself POSIX specifies that rename(2) should do nothing and return success. This condition is checked in vfs_rename(). However it won't detect hard links on overlayfs where these are given separate inodes on the overlayfs layer. Overlayfs itself detects this condition and returns success without doing anything, but then vfs_rename() will proceed as if this was a successful rename (detach_mounts(), d_move()). The correct thing to do is to detect this condition before even calling into overlayfs. This patch does this by calling vfs_select_inode() to get the underlying inodes. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.2+
2016-05-11vfs: add vfs_select_inode() helperMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.2+
2016-05-10f2fs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-10afs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-10befs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-10befs: constify stuff a bitAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-10Revert "proc/base: make prompt shell start from new line after executing ↵Robin Humble
"cat /proc/$pid/wchan"" This reverts the 4.6-rc1 commit 7e2bc81da333 ("proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan") because it breaks /proc/$PID/whcan formatting in ps and top. Revert also because the patch is inconsistent - it adds a newline at the end of only the '0' wchan, and does not add a newline when /proc/$PID/wchan contains a symbol name. eg. $ ps -eo pid,stat,wchan,comm PID STAT WCHAN COMMAND ... 1189 S - dbus-launch 1190 Ssl 0 dbus-daemon 1198 Sl 0 lightdm 1299 Ss ep_pol systemd 1301 S - (sd-pam) 1304 Ss wait sh Signed-off-by: Robin Humble <plaguedbypenguins@gmail.com> Cc: Minfei Huang <mnfhuang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-09isofs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespacesSerge E. Hallyn
Patch summary: When showing a cgroupfs entry in mountinfo, show the path of the mount root dentry relative to the reader's cgroup namespace root. Short explanation (courtesy of mkerrisk): If we create a new cgroup namespace, then we want both /proc/self/cgroup and /proc/self/mountinfo to show cgroup paths that are correctly virtualized with respect to the cgroup mount point. Previous to this patch, /proc/self/cgroup shows the right info, but /proc/self/mountinfo does not. Long version: When a uid 0 task which is in freezer cgroup /a/b, unshares a new cgroup namespace, and then mounts a new instance of the freezer cgroup, the new mount will be rooted at /a/b. The root dentry field of the mountinfo entry will show '/a/b'. cat > /tmp/do1 << EOF mount -t cgroup -o freezer freezer /mnt grep freezer /proc/self/mountinfo EOF unshare -Gm bash /tmp/do1 > 330 160 0:34 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,freezer > 355 133 0:34 /a/b /mnt rw,relatime - cgroup freezer rw,freezer The task's freezer cgroup entry in /proc/self/cgroup will simply show '/': grep freezer /proc/self/cgroup 9:freezer:/ If instead the same task simply bind mounts the /a/b cgroup directory, the resulting mountinfo entry will again show /a/b for the dentry root. However in this case the task will find its own cgroup at /mnt/a/b, not at /mnt: mount --bind /sys/fs/cgroup/freezer/a/b /mnt 130 25 0:34 /a/b /mnt rw,nosuid,nodev,noexec,relatime shared:21 - cgroup cgroup rw,freezer In other words, there is no way for the task to know, based on what is in mountinfo, which cgroup directory is its own. Example (by mkerrisk): First, a little script to save some typing and verbiage: echo -e "\t/proc/self/cgroup:\t$(cat /proc/self/cgroup | grep freezer)" cat /proc/self/mountinfo | grep freezer | awk '{print "\tmountinfo:\t\t" $4 "\t" $5}' Create cgroup, place this shell into the cgroup, and look at the state of the /proc files: 2653 2653 # Our shell 14254 # cat(1) /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer Create a shell in new cgroup and mount namespaces. The act of creating a new cgroup namespace causes the process's current cgroups directories to become its cgroup root directories. (Here, I'm using my own version of the "unshare" utility, which takes the same options as the util-linux version): Look at the state of the /proc files: /proc/self/cgroup: 10:freezer:/ mountinfo: / /sys/fs/cgroup/freezer The third entry in /proc/self/cgroup (the pathname of the cgroup inside the hierarchy) is correctly virtualized w.r.t. the cgroup namespace, which is rooted at /a/b in the outer namespace. However, the info in /proc/self/mountinfo is not for this cgroup namespace, since we are seeing a duplicate of the mount from the old mount namespace, and the info there does not correspond to the new cgroup namespace. However, trying to create a new mount still doesn't show us the right information in mountinfo: # propagating to other mountns /proc/self/cgroup: 7:freezer:/ mountinfo: /a/b /mnt/freezer The act of creating a new cgroup namespace caused the process's current freezer directory, "/a/b", to become its cgroup freezer root directory. In other words, the pathname directory of the directory within the newly mounted cgroup filesystem should be "/", but mountinfo wrongly shows us "/a/b". The consequence of this is that the process in the cgroup namespace cannot correctly construct the pathname of its cgroup root directory from the information in /proc/PID/mountinfo. With this patch, the dentry root field in mountinfo is shown relative to the reader's cgroup namespace. So the same steps as above: /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: /../.. /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: / /mnt/freezer cgroup.clone_children freezer.parent_freezing freezer.state tasks cgroup.procs freezer.self_freezing notify_on_release 3164 2653 # First shell that placed in this cgroup 3164 # Shell started by 'unshare' 14197 # cat(1) Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Tested-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-09get_acorn_filename(): deobfuscate a bitAl Viro
Lots of Idiotic Silly Parentheses is -> that way... What that condition checks is that there's exactly 32 bytes between the end of name and the end of entire drectory record. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09btrfs: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09logfs: no need to lock directory in lseekAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09switch ecryptfs to ->iterate_sharedAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09Merge branch 'for-linus' into work.lookupsAl Viro
2016-05-099p: switch to ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09fat: switch to ->iterate_shared()Al Viro
... and make that weird ioctl lock directory only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09romfs, squashfs: switch to ->iterate_shared()Al Viro
don't need to lock directory in ->llseek(), either Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09more trivial ->iterate_shared conversionsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09kernfs: no point locking directory around that generic_file_llseek()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09configfs_readdir(): make safe under shared lockAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09nfs: per-name sillyunlink exclusionAl Viro
use d_alloc_parallel() for sillyunlink/lookup exclusion and explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() - a reader) for rmdir/sillyunlink one. That ought to make lookup/readdir/!O_CREAT atomic_open really parallel on NFS. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-08get_rock_ridge_filename(): handle malformed NM entriesAl Viro
Payloads of NM entries are not supposed to contain NUL. When we run into such, only the part prior to the first NUL goes into the concatenation (i.e. the directory entry name being encoded by a bunch of NM entries). We do stop when the amount collected so far + the claimed amount in the current NM entry exceed 254. So far, so good, but what we return as the total length is the sum of *claimed* sizes, not the actual amount collected. And that can grow pretty large - not unlimited, since you'd need to put CE entries in between to be able to get more than the maximum that could be contained in one isofs directory entry / continuation chunk and we are stop once we'd encountered 32 CEs, but you can get about 8Kb easily. And that's what will be passed to readdir callback as the name length. 8Kb __copy_to_user() from a buffer allocated by __get_free_page() Cc: stable@vger.kernel.org # 0.98pl6+ (yes, really) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-07efivarfs: Make efivarfs_file_ioctl() staticPeter Jones
There are no callers except through the file_operations struct below this, so it should be static like everything else here. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462570771-13324-6-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07efi: Merge boolean flag argumentsJulia Lawall
The parameters atomic and duplicates of efivar_init always have opposite values. Drop the parameter atomic, replace the uses of !atomic with duplicates, and update the call sites accordingly. The code using duplicates is slightly reorganized with an 'else', to avoid duplicating the lock code. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Saurabh Sengar <saurabh.truth@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vaishali Thakkar <vaishali.thakkar@oracle.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462570771-13324-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-06proc: prevent accessing /proc/<PID>/environ until it's readyMathias Krause
If /proc/<PID>/environ gets read before the envp[] array is fully set up in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to read more bytes than are actually written, as env_start will already be set but env_end will still be zero, making the range calculation underflow, allowing to read beyond the end of what has been written. Fix this as it is done for /proc/<PID>/cmdline by testing env_end for zero. It is, apparently, intentionally set last in create_*_tables(). This bug was found by the PaX size_overflow plugin that detected the arithmetic underflow of 'this_len = env_end - (env_start + src)' when env_end is still zero. The expected consequence is that userland trying to access /proc/<PID>/environ of a not yet fully set up process may get inconsistent data as we're in the middle of copying in the environment variables. Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461 Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Pax Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>