* 4.9/tmp-05a906d:
Linux 4.9.56
Revert "socket, bpf: fix possible use after free"
Linux 4.9.55
KVM: x86: fix singlestepping over syscall
f2fs: don't allow encrypted operations without keys
ext4: don't allow encrypted operations without keys
ext4: Don't clear SGID when inheriting ACLs
ext4: fix data corruption for mmap writes
vfs: deny copy_file_range() for non regular files
sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs
mmc: core: add driver strength selection when selecting hs400es
nvme-pci: Use PCI bus address for data/queues in CMB
drm/i915/bios: ignore HDMI on port A
brcmfmac: setup passive scan if requested by user-space
brcmfmac: add length check in brcmf_cfg80211_escan_handler()
scsi: sd: Do not override max_sectors_kb sysfs setting
iwlwifi: add workaround to disable wide channels in 5GHz
iwlwifi: mvm: use IWL_HCMD_NOCOPY for MCAST_FILTER_CMD
netlink: fix nla_put_{u8,u16,u32} for KASAN
rocker: fix rocker_tlv_put_* functions for KASAN
HID: wacom: bits shifted too much for 9th and 10th buttons
HID: wacom: Always increment hdev refcount within wacom_get_hdev_data
HID: wacom: leds: Don't try to control the EKR's read-only LEDs
HID: i2c-hid: allocate hid buffers for real worst case
ftrace: Fix kmemleak in unregister_ftrace_graph
stm class: Fix a use-after-free
Drivers: hv: fcopy: restore correct transfer length
driver core: platform: Don't read past the end of "driver_override" buffer
percpu: make this_cpu_generic_read() atomic w.r.t. interrupts
powerpc/tm: Fix illegal TM state in signal handler
powerpc/64s: Use emergency stack for kernel TM Bad Thing program checks
socket, bpf: fix possible use after free
net: rtnetlink: fix info leak in RTM_GETSTATS call
tipc: use only positive error codes in messages
ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path
ip6_gre: ip6gre_tap device should keep dst
netlink: do not proceed if dump's start() errs
net: Set sk_prot_creator when cloning sockets to the right proto
packet: only test po->has_vnet_hdr once in packet_snd
packet: in packet_do_bind, test fanout with bind_lock held
net: dsa: Fix network device registration order
tun: bail out from tun_get_user() if the skb is empty
l2tp: fix race condition in l2tp_tunnel_delete
l2tp: Avoid schedule while atomic in exit_net
vti: fix use after free in vti_tunnel_xmit/vti6_tnl_xmit
net: qcom/emac: specify the correct size when mapping a DMA buffer
net_sched: always reset qdisc backlog in qdisc_reset()
isdn/i4l: fetch the ppp_write buffer in one shot
bpf: one perf event close won't free bpf program attached by another perf event
packet: hold bind lock when rebinding to fanout hook
net: emac: Fix napi poll list corruption
tcp: fastopen: fix on syn-data transmit failure
net/sched: cls_matchall: fix crash when used with classful qdisc
ip6_tunnel: do not allow loading ip6_tunnel if ipv6 is disabled in cmdline
net: phy: Fix mask value write on gmii2rgmii converter speed register
ip6_gre: skb_push ipv6hdr before packing the header in ip6gre_header
udpv6: Fix the checksum computation when HW checksum does not apply
tcp: fix data delivery rate
bpf/verifier: reject BPF_ALU64|BPF_END
tcp: update skb->skb_mstamp more carefully
sctp: potential read out of bounds in sctp_ulpevent_type_enabled()
net: sched: fix use-after-free in tcf_action_destroy and tcf_del_walker
mlxsw: spectrum: Prevent mirred-related crash on removal
ALSA: usx2y: Suppress kernel warning at page allocation failures
Revert "ALSA: echoaudio: purge contradictions between dimension matrix members and total number of members"
ALSA: compress: Remove unused variable
lsm: fix smack_inode_removexattr and xattr_getsecurity memleak
lib/ratelimit.c: use deferred printk() version
mm, oom_reaper: skip mm structs with mmu notifiers
staging: vchiq_2835_arm: Fix NULL ptr dereference in free_pagelist
uwb: ensure that endpoint is interrupt
uwb: properly check kthread_run return value
iio: adc: mcp320x: Fix oops on module unload
iio: adc: mcp320x: Fix readout of negative voltages
iio: ad7793: Fix the serial interface reset
IIO: BME280: Updates to Humidity readings need ctrl_reg write!
iio: core: Return error for failed read_reg
staging: iio: ad7192: Fix - use the dedicated reset function avoiding dma from stack.
iio: ad_sigma_delta: Implement a dedicated reset function
iio: adc: twl4030: Disable the vusb3v1 rugulator in the error handling path of 'twl4030_madc_probe()'
iio: adc: twl4030: Fix an error handling path in 'twl4030_madc_probe()'
Revert "xhci: Limit USB2 port wake support for AMD Promontory hosts"
xhci: set missing SuperSpeedPlus Link Protocol bit in roothub descriptor
xhci: Fix sleeping with spin_lock_irq() held in ASmedia 1042A workaround
xhci: fix finding correct bus_state structure for USB 3.1 hosts
USB: fix out-of-bounds in usb_set_configuration
usb: Increase quirk delay for USB devices
USB: core: harden cdc_parse_cdc_header
USB: uas: fix bug in handling of alternate settings
USB: g_mass_storage: Fix deadlock when driver is unbound
usb: gadget: mass_storage: set msg_registered after msg registered
USB: devio: Don't corrupt user memory
USB: dummy-hcd: Fix erroneous synchronization change
USB: dummy-hcd: fix infinite-loop resubmission bug
USB: dummy-hcd: fix connection failures (wrong speed)
USB: cdc-wdm: ignore -EPIPE from GetEncapsulatedResponse
usb: pci-quirks.c: Corrected timeout values used in handshake
ALSA: usb-audio: Check out-of-bounds access by corrupted buffer descriptor
usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction
usb: renesas_usbhs: fix the BCLR setting condition for non-DCP pipe
usb-storage: fix bogus hardware error messages for ATA pass-thru devices
usb-storage: unusual_devs entry to fix write-access regression for Seagate external drives
usb: gadget: udc: renesas_usb3: Fix return value of usb3_write_pipe()
usb: gadget: udc: renesas_usb3: fix Pn_RAMMAP.Pn_MPKT value
usb: gadget: udc: renesas_usb3: fix for no-data control transfer
usb: gadget: udc: atmel: set vbus irqflags explicitly
USB: gadgetfs: fix copy_to_user while holding spinlock
USB: gadgetfs: Fix crash caused by inadequate synchronization
Linux 4.9.54
s390/mm: make pmdp_invalidate() do invalidation only
ttpci: address stringop overflow warning
ALSA: au88x0: avoid theoretical uninitialized access
ASoC: rt5660: remove double const
ASoC: rt5659: drop double const
ASoC: rt5514: fix gcc-7 warning
ARM: remove duplicate 'const' annotations'
IB/qib: fix false-postive maybe-uninitialized warning
tools/power turbostat: bugfix: GFXMHz column not changing
ARM: dts: BCM5301X: Fix memory start address
libata: transport: Remove circular dependency at free time
ASoC: wm_adsp: Return an error on write to a disabled volatile control
xfs: remove kmem_zalloc_greedy
i2c: meson: fix wrong variable usage in meson_i2c_put_data
netfilter: nf_tables: set pktinfo->thoff at AH header if found
md/raid10: submit bio directly to replacement disk
rds: ib: add error handle
mm/cgroup: avoid panic when init with low memory
iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
x86/acpi: Restore the order of CPU IDs
cpufreq: intel_pstate: Update pid_params.sample_rate_ns in pid_param_set()
ibmvnic: Free tx/rx scrq pointer array when releasing sub-crqs
nfs: make nfs4_cb_sv_ops static
parisc: perf: Fix potential NULL pointer dereference
netfilter: nfnl_cthelper: fix incorrect helper->expect_class_max
nvme-rdma: handle cpu unplug when re-establishing the controller
MIPS: smp-cps: Fix retrieval of VPE mask on big endian CPUs
exynos-gsc: Do not swap cb/cr for semi planar formats
iommu/exynos: Block SYSMMU while invalidating FLPD cache
MIPS: IRQ Stack: Unwind IRQ stack onto task stack
netfilter: invoke synchronize_rcu after set the _hook_ to NULL
drivers/rapidio/devices/tsi721.c: make module parameter variable name unique
kasan: do not sanitize kexec purgatory
hugetlbfs: initialize shared policy as part of inode allocation
sata_via: Enable hotplug only on VT6421
Btrfs: fix potential use-after-free for cloned bio
Btrfs: fix segmentation fault when doing dio read
bridge: netlink: register netdevice before executing changelink
mmc: sdio: fix alignment issue in struct sdio_func
qed: Fix possible system hang in the dcbnl-getdcbx() path.
net: dsa: b53: Include IMP/CPU port in dumb forwarding mode
udp: disable inner UDP checksum offloads in IPsec case
usb: plusb: Add support for PL-27A1
team: fix memory leaks
net/packet: check length in getsockopt() called with PACKET_HDRLEN
net: core: Prevent from dereferencing null pointer when releasing SKB
lkdtm: Fix Oops when unloading the module
mips: ath79: clock:- Unmap region obtained by of_iomap
MIPS: Lantiq: Fix another request_mem_region() return code check
HID: wacom: release the resources before leaving despite devm
drm: mali-dp: Fix transposed horizontal/vertical flip
drm: mali-dp: Fix destination size handling when rotating
ASoC: dapm: fix some pointer error handling
rtl8xxxu: Add additional USB IDs for rtl8192eu devices
usb: chipidea: vbus event may exist before starting gadget
iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged'
spi: pxa2xx: Add support for Intel Gemini Lake
ath10k: prevent sta pointer rcu violation
audit: log 32-bit socketcalls
ASoC: dapm: handle probe deferrals
partitions/efi: Fix integer overflow in GPT size calculation
sfc: get PIO buffer size from the NIC
USB: serial: mos7840: fix control-message error handling
USB: serial: mos7720: fix control-message error handling
drm/amdkfd: fix improper return value on error
arm: dts: mt2701: Add subsystem clock controller device nodes
IB/ipoib: Replace list_del of the neigh->list with list_del_init
IB/ipoib: rtnl_unlock can not come after free_netdev
IB/ipoib: Fix deadlock over vlan_mutex
serial: 8250_port: Remove dangerous pr_debug()
tty: goldfish: Fix a parameter of a call to free_irq
serial: 8250: moxa: Store num_ports in brd
drm/i915/psr: disable psr2 for resolution greater than 32X20
ARM: 8635/1: nommu: allow enabling REMAP_VECTORS_TO_RAM
IB/rxe: Fix a MR reference leak in check_rkey()
IB/rxe: Add a runtime check in alloc_index()
iio: adc: hx711: Add DT binding for avia,hx711
iio: adc: axp288: Drop bogus AXP288_ADC_TS_PIN_CTRL register modifications
iio: adc: imx25-gcq: Fix module autoload
hwmon: (gl520sm) Fix overflows and crash seen when writing into limit attributes
usb: make the MTK XHCI driver compile for older MIPS SoCs
clk/axs10x: Clear init field in driver probe
sh_eth: use correct name for ECMR_MPDE bit
reset: ti_syscon: fix a ti_syscon_reset_status issue
extcon: axp288: Use vbus-valid instead of -present to determine cable presence
igb: re-assign hw address pointer on reset after PCI error
ARM: dts: am335x-chilisom: Wakeup from RTC-only state by power on event
scsi: be2iscsi: Add checks to validate CID alloc/free
power: supply: axp288_fuel_gauge: Fix fuel_gauge_reg_readb return on error
MIPS: ralink: Fix incorrect assignment on ralink_soc
MIPS: ralink: Fix a typo in the pinmux setup.
MIPS: Ensure bss section ends on a long-aligned address
ARM: dts: r8a7790: Use R-Car Gen 2 fallback binding for msiof nodes
RDS: RDMA: Fix the composite message user notification
clk: sunxi-ng: fix PLL_CPUX adjusting on H3
ARM: dts: exynos: Add CPU OPPs for Exynos4412 Prime
drm/i915: Fix the overlay frontbuffer tracking
GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next
drm: bridge: add DT bindings for TI ths8135
drm_fourcc: Fix DRM_FORMAT_MOD_LINEAR #define
FROMLIST: binder: fix use-after-free in binder_transaction()
FROMLIST: binder: fix an ret value override
FROMLIST: binder: fix memory corruption in binder_transaction binder
Conflicts:
mm/oom_kill.c
sound/usb/card.c
Change-Id: I8b32fbdaa2be959a4149cf07d0bda16b75eeacbc
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
commit 57e7ba04d422c3d41c8426380303ec9b7533ded9 upstream.
security_inode_getsecurity() provides the text string value
of a security attribute. It does not provide a "secctx".
The code in xattr_getsecurity() that calls security_inode_getsecurity()
and then calls security_release_secctx() happened to work because
SElinux and Smack treat the attribute and the secctx the same way.
It fails for cap_inode_getsecurity(), because that module has no
secctx that ever needs releasing. It turns out that Smack is the
one that's doing things wrong by not allocating memory when instructed
to do so by the "alloc" parameter.
The fix is simple enough. Change the security_release_secctx() to
kfree() because it isn't a secctx being returned by
security_inode_getsecurity(). Change Smack to allocate the string when
told to do so.
Note: this also fixes memory leaks for LSMs which implement
inode_getsecurity but not release_secctx, such as capabilities.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Casey Schauflerauthored and Greg Kroah-Hartmancommited 2017-10-12 11:51:19 +02:00
Mark all of the registration hooks as __ro_after_init (via the
__lsm_ro_after_init macro).
Change-Id: I07d4286051373aac1e76442afc7ca8fab3065b60
Signed-off-by: James Morris <james.l.morris@oracle.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>
Git-commit: ca97d939db114c8d1619e10a3b82af8615372dae
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
James Morrisauthored and Olav Haugancommited 2017-07-25 15:01:41 -07:00
Pull vfs xattr updates from Al Viro:
"xattr stuff from Andreas
This completes the switch to xattr_handler ->get()/->set() from
->getxattr/->setxattr/->removexattr"
* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Remove {get,set,remove}xattr inode operations
xattr: Stop calling {get,set,remove}xattr inode operations
vfs: Check for the IOP_XATTR flag in listxattr
xattr: Add __vfs_{get,set,remove}xattr helpers
libfs: Use IOP_XATTR flag for empty directory handling
vfs: Use IOP_XATTR flag for bad-inode handling
vfs: Add IOP_XATTR inode operations flag
vfs: Move xattr_resolve_name to the front of fs/xattr.c
ecryptfs: Switch to generic xattr handlers
sockfs: Get rid of getxattr iop
sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
kernfs: Switch to generic xattr handlers
hfs: Switch to generic xattr handlers
jffs2: Remove jffs2_{get,set,remove}xattr macros
xattr: Remove unnecessary NULL attribute name check
Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations. Switch to helper functions and test for the IOP_XATTR
flag instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Andreas Gruenbacherauthored and Al Virocommited 2016-10-07 20:10:44 -04:00
Under a strict subject/object security policy delivering a
signal or delivering network IPC could be considered either
a write or an append operation. The original choice to make
both write operations leads to an issue where IPC delivery
is desired under policy, but delivery of signals is not.
This patch provides the option of making signal delivery
an append operation, allowing Smack rules that deny signal
delivery while allowing IPC. This was requested for Tizen.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Markus Elfringauthored and Casey Schauflercommited 2016-08-23 09:58:21 -07:00
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled
either built-in or as a module, use that macro instead of open coding
the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Javier Martinez Canillasauthored and Paul Moorecommited 2016-08-08 13:08:25 -04:00
Pull security subsystem updates from James Morris:
"Highlights:
- TPM core and driver updates/fixes
- IPv6 security labeling (CALIPSO)
- Lots of Apparmor fixes
- Seccomp: remove 2-phase API, close hole where ptrace can change
syscall #"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits)
apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)
tpm: Factor out common startup code
tpm: use devm_add_action_or_reset
tpm2_i2c_nuvoton: add irq validity check
tpm: read burstcount from TPM_STS in one 32-bit transaction
tpm: fix byte-order for the value read by tpm2_get_tpm_pt
tpm_tis_core: convert max timeouts from msec to jiffies
apparmor: fix arg_size computation for when setprocattr is null terminated
apparmor: fix oops, validate buffer size in apparmor_setprocattr()
apparmor: do not expose kernel stack
apparmor: fix module parameters can be changed after policy is locked
apparmor: fix oops in profile_unpack() when policy_db is not present
apparmor: don't check for vmalloc_addr if kvzalloc() failed
apparmor: add missing id bounds check on dfa verification
apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
apparmor: use list_next_entry instead of list_entry_next
apparmor: fix refcount race when finding a child profile
apparmor: fix ref count leak when profile sha1 hash is read
apparmor: check that xindex is in trans_table bounds
...
Pull userns vfs updates from Eric Biederman:
"This tree contains some very long awaited work on generalizing the
user namespace support for mounting filesystems to include filesystems
with a backing store. The real world target is fuse but the goal is
to update the vfs to allow any filesystem to be supported. This
patchset is based on a lot of code review and testing to approach that
goal.
While looking at what is needed to support the fuse filesystem it
became clear that there were things like xattrs for security modules
that needed special treatment. That the resolution of those concerns
would not be fuse specific. That sorting out these general issues
made most sense at the generic level, where the right people could be
drawn into the conversation, and the issues could be solved for
everyone.
At a high level what this patchset does a couple of simple things:
- Add a user namespace owner (s_user_ns) to struct super_block.
- Teach the vfs to handle filesystem uids and gids not mapping into
to kuids and kgids and being reported as INVALID_UID and
INVALID_GID in vfs data structures.
By assigning a user namespace owner filesystems that are mounted with
only user namespace privilege can be detected. This allows security
modules and the like to know which mounts may not be trusted. This
also allows the set of uids and gids that are communicated to the
filesystem to be capped at the set of kuids and kgids that are in the
owning user namespace of the filesystem.
One of the crazier corner casees this handles is the case of inodes
whose i_uid or i_gid are not mapped into the vfs. Most of the code
simply doesn't care but it is easy to confuse the inode writeback path
so no operation that could cause an inode write-back is permitted for
such inodes (aka only reads are allowed).
This set of changes starts out by cleaning up the code paths involved
in user namespace permirted mounts. Then when things are clean enough
adds code that cleanly sets s_user_ns. Then additional restrictions
are added that are possible now that the filesystem superblock
contains owner information.
These changes should not affect anyone in practice, but there are some
parts of these restrictions that are changes in behavior.
- Andy's restriction on suid executables that does not honor the
suid bit when the path is from another mount namespace (think
/proc/[pid]/fd/) or when the filesystem was mounted by a less
privileged user.
- The replacement of the user namespace implicit setting of MNT_NODEV
with implicitly setting SB_I_NODEV on the filesystem superblock
instead.
Using SB_I_NODEV is a stronger form that happens to make this state
user invisible. The user visibility can be managed but it caused
problems when it was introduced from applications reasonably
expecting mount flags to be what they were set to.
There is a little bit of work remaining before it is safe to support
mounting filesystems with backing store in user namespaces, beyond
what is in this set of changes.
- Verifying the mounter has permission to read/write the block device
during mount.
- Teaching the integrity modules IMA and EVM to handle filesystems
mounted with only user namespace root and to reduce trust in their
security xattrs accordingly.
- Capturing the mounters credentials and using that for permission
checks in d_automount and the like. (Given that overlayfs already
does this, and we need the work in d_automount it make sense to
generalize this case).
Furthermore there are a few changes that are on the wishlist:
- Get all filesystems supporting posix acls using the generic posix
acls so that posix_acl_fix_xattr_from_user and
posix_acl_fix_xattr_to_user may be removed. [Maintainability]
- Reducing the permission checks in places such as remount to allow
the superblock owner to perform them.
- Allowing the superblock owner to chown files with unmapped uids and
gids to something that is mapped so the files may be treated
normally.
I am not considering even obvious relaxations of permission checks
until it is clear there are no more corner cases that need to be
locked down and handled generically.
Many thanks to Seth Forshee who kept this code alive, and putting up
with me rewriting substantial portions of what he did to handle more
corner cases, and for his diligent testing and reviewing of my
changes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits)
fs: Call d_automount with the filesystems creds
fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns
evm: Translate user/group ids relative to s_user_ns when computing HMAC
dquot: For now explicitly don't support filesystems outside of init_user_ns
quota: Handle quota data stored in s_user_ns in quota_setxquota
quota: Ensure qids map to the filesystem
vfs: Don't create inodes with a uid or gid unknown to the vfs
vfs: Don't modify inodes with a uid or gid unknown to the vfs
cred: Reject inodes with invalid ids in set_create_file_as()
fs: Check for invalid i_uid in may_follow_link()
vfs: Verify acls are valid within superblock's s_user_ns.
userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS
fs: Refuse uid/gid changes which don't map into s_user_ns
selinux: Add support for unprivileged mounts from user namespaces
Smack: Handle labels consistently in untrusted mounts
Smack: Add support for unprivileged mounts from user namespaces
fs: Treat foreign mounts as nosuid
fs: Limit file caps to the user namespace of the super block
userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag
userns: Remove implicit MNT_NODEV fragility.
...
This makes it possible to route the error to the appropriate
labelling engine. CALIPSO is far less verbose than CIPSO
when encountering a bogus packet, so there is no need for a
CALIPSO error handler.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Huw Daviesauthored and Paul Moorecommited 2016-06-27 15:06:16 -04:00
The SMACK64, SMACK64EXEC, and SMACK64MMAP labels are all handled
differently in untrusted mounts. This is confusing and
potentically problematic. Change this to handle them all the same
way that SMACK64 is currently handled; that is, read the label
from disk and check it at use time. For SMACK64 and SMACK64MMAP
access is denied if the label does not match smk_root. To be
consistent with suid, a SMACK64EXEC label which does not match
smk_root will still allow execution of the file but will not run
with the label supplied in the xattr.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Seth Forsheeauthored and Eric W. Biedermancommited 2016-06-24 11:02:22 -05:00
Security labels from unprivileged mounts cannot be trusted.
Ideally for these mounts we would assign the objects in the
filesystem the same label as the inode for the backing device
passed to mount. Unfortunately it's currently impossible to
determine which inode this is from the LSM mount hooks, so we
settle for the label of the process doing the mount.
This label is assigned to s_root, and also to smk_default to
ensure that new inodes receive this label. The transmute property
is also set on s_root to make this behavior more explicit, even
though it is technically not necessary.
If a filesystem has existing security labels, access to inodes is
permitted if the label is the same as smk_root, otherwise access
is denied. The SMACK64EXEC xattr is completely ignored.
Explicit setting of security labels continues to require
CAP_MAC_ADMIN in init_user_ns.
Altogether, this ensures that filesystem objects are not
accessible to subjects which cannot already access the backing
store, that MAC is not violated for any objects in the fileystem
which are already labeled, and that a user cannot use an
unprivileged mount to gain elevated MAC privileges.
sysfs, tmpfs, and ramfs are already mountable from user
namespaces and support security labels. We can't rule out the
possibility that these filesystems may already be used in mounts
from user namespaces with security lables set from the init
namespace, so failing to trust lables in these filesystems may
introduce regressions. It is safe to trust labels from these
filesystems, since the unprivileged user does not control the
backing store and thus cannot supply security labels, so an
explicit exception is made to trust labels from these
filesystems.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Seth Forsheeauthored and Eric W. Biedermancommited 2016-06-24 10:40:42 -05:00
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time. It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.
A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.
Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kill with signal number 0 is commonly used for checking PID existence.
Smack treated such cases like any other kills, although no signal is
actually delivered when sig == 0.
Checking permissions when sig == 0 didn't prevent an unprivileged caller
from learning whether PID exists or not. When it existed, kernel returned
EPERM, when it didn't - ESRCH. The only effect of policy check in such
case is noise in audit logs.
This change lets Smack silently ignore kill() invocations with sig == 0.
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Rafal Krypaauthored and Casey Schauflercommited 2016-06-08 13:52:31 -07:00
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Before this commit, removing the access property of
a file, aka, the extended attribute security.SMACK64
was not effictive until the cache had been cleaned.
This patch fixes that problem.
Signed-off-by: José Bollo <jobol@nonadev.net>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
José Bolloauthored and Casey Schauflercommited 2016-02-16 09:56:35 -08:00
Prior to the 4.2 kernel there no no harm in providing
a security module hook that does nothing, as the default
hook would get called if the module did not supply one.
With the list based infrastructure an empty hook adds
overhead. This patch removes the three Smack hooks that
don't actually do anything.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jann Hornauthored and Linus Torvaldscommited 2016-01-20 17:09:18 -08:00
Pull security subsystem updates from James Morris:
- EVM gains support for loading an x509 cert from the kernel
(EVM_LOAD_X509), into the EVM trusted kernel keyring.
- Smack implements 'file receive' process-based permission checking for
sockets, rather than just depending on inode checks.
- Misc enhancments for TPM & TPM2.
- Cleanups and bugfixes for SELinux, Keys, and IMA.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits)
selinux: Inode label revalidation performance fix
KEYS: refcount bug fix
ima: ima_write_policy() limit locking
IMA: policy can be updated zero times
selinux: rate-limit netlink message warnings in selinux_nlmsg_perm()
selinux: export validatetrans decisions
gfs2: Invalid security labels of inodes when they go invalid
selinux: Revalidate invalid inode security labels
security: Add hook to invalidate inode security labels
selinux: Add accessor functions for inode->i_security
security: Make inode argument of inode_getsecid non-const
security: Make inode argument of inode_getsecurity non-const
selinux: Remove unused variable in selinux_inode_init_security
keys, trusted: seal with a TPM2 authorization policy
keys, trusted: select hash algorithm for TPM2 chips
keys, trusted: fix: *do not* allow duplicate key options
tpm_ibmvtpm: properly handle interrupted packet receptions
tpm_tis: Tighten IRQ auto-probing
tpm_tis: Refactor the interrupt setup
tpm_tis: Get rid of the duplicate IRQ probing code
...
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make the inode argument of the inode_getsecid hook non-const so that we
can use it to revalidate invalid security labels.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Andreas Gruenbacherauthored and Paul Moorecommited 2015-12-24 11:09:39 -05:00
Make the inode argument of the inode_getsecurity hook non-const so that
we can use it to revalidate invalid security labels.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Andreas Gruenbacherauthored and Paul Moorecommited 2015-12-24 11:09:39 -05:00
Smack security handler for sendmsg() syscall
is vulnerable to type confusion issue what
can allow to privilege escalation into root
or cause denial of service.
A malicious attacker can create socket of one
type for example AF_UNIX and pass is into
sendmsg() function ensuring that this is
AF_INET socket.
Remedy
Do not trust user supplied data.
Proposed fix below.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Signed-off-by: Mateusz Fruba <m.fruba@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Roman Kubiakauthored and Casey Schauflercommited 2015-12-17 10:21:56 -08:00
Add a nfs_listxattr operation. Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Andreas Gruenbacherauthored and Al Virocommited 2015-12-13 19:45:47 -05:00
The existing file receive hook checks for access on
the file inode even for UDS. This is not right, as
the inode is not used by Smack to make access checks
for sockets. This change checks for an appropriate
access relationship between the receiving (current)
process and the socket. If the process can't write
to the socket's send label or the socket's receive
label can't write to the process fail.
This will allow the legitimate cases, where the
socket sender and socket receiver can freely communicate.
Only strangly set socket labels should cause a problem.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Pull networking fixes from David Miller:
1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet.
2) Several spots need to get to the original listner for SYN-ACK
packets, most spots got this ok but some were not. Whilst covering
the remaining cases, create a helper to do this. From Eric Dumazet.
3) Missiing check of return value from alloc_netdev() in CAIF SPI code,
from Rasmus Villemoes.
4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich.
5) Use after free in mvneta driver, from Justin Maggard.
6) Fix race on dst->flags access in dst_release(), from Eric Dumazet.
7) Add missing ZLIB_INFLATE dependency for new qed driver. From Arnd
Bergmann.
8) Fix multicast getsockopt deadlock, from WANG Cong.
9) Fix deadlock in btusb, from Kuba Pawlak.
10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6
counter state. From Sabrina Dubroca.
11) Fix packet_bind() race, which can cause lost notifications, from
Francesco Ruggeri.
12) Fix MAC restoration in qlcnic driver during bonding mode changes,
from Jarod Wilson.
13) Revert bridging forward delay change which broke libvirt and other
userspace things, from Vlad Yasevich.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
Revert "bridge: Allow forward delay to be cfgd when STP enabled"
bpf_trace: Make dependent on PERF_EVENTS
qed: select ZLIB_INFLATE
net: fix a race in dst_release()
net: mvneta: Fix memory use after free.
net: Documentation: Fix default value tcp_limit_output_bytes
macvtap: Resolve possible __might_sleep warning in macvtap_do_read()
mvneta: add FIXED_PHY dependency
net: caif: check return value of alloc_netdev
net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA
drivers: net: xgene: fix RGMII 10/100Mb mode
netfilter: nft_meta: use skb_to_full_sk() helper
net_sched: em_meta: use skb_to_full_sk() helper
sched: cls_flow: use skb_to_full_sk() helper
netfilter: xt_owner: use skb_to_full_sk() helper
smack: use skb_to_full_sk() helper
net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()
bpf: doc: correct arch list for supported eBPF JIT
dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put"
bonding: fix panic on non-ARPHRD_ETHER enslave failure
...
This module wants to access sk->sk_security, which is not
available for request sockets.
Fixes: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2015-11-08 20:56:38 -05:00
Pull security subsystem update from James Morris:
"This is mostly maintenance updates across the subsystem, with a
notable update for TPM 2.0, and addition of Jarkko Sakkinen as a
maintainer of that"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits)
apparmor: clarify CRYPTO dependency
selinux: Use a kmem_cache for allocation struct file_security_struct
selinux: ioctl_has_perm should be static
selinux: use sprintf return value
selinux: use kstrdup() in security_get_bools()
selinux: use kmemdup in security_sid_to_context_core()
selinux: remove pointless cast in selinux_inode_setsecurity()
selinux: introduce security_context_str_to_sid
selinux: do not check open perm on ftruncate call
selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default
KEYS: Merge the type-specific data with the payload data
KEYS: Provide a script to extract a module signature
KEYS: Provide a script to extract the sys cert list from a vmlinux file
keys: Be more consistent in selection of union members used
certs: add .gitignore to stop git nagging about x509_certificate_list
KEYS: use kvfree() in add_key
Smack: limited capability for changing process label
TPM: remove unnecessary little endian conversion
vTPM: support little endian guests
char: Drop owner assignment from i2c_driver
...
This feature introduces new kernel interface:
- <smack_fs>/relabel-self - for setting transition labels list
This list is used to control smack label transition mechanism.
List is set by, and per process. Process can transit to new label only if
label is on the list. Only process with CAP_MAC_ADMIN capability can add
labels to this list. With this list, process can change it's label without
CAP_MAC_ADMIN but only once. After label changing, list is unset.
Changes in v2:
* use list_for_each_entry instead of _rcu during label write
* added missing description in security/Smack.txt
Changes in v3:
* squashed into one commit
Changes in v4:
* switch from global list to per-task list
* since the per-task list is accessed only by the task itself
there is no need to use synchronization mechanisms on it
Changes in v5:
* change smackfs interface of relabel-self to the one used for onlycap
multiple labels are accepted, separated by space, which
replace the previous list upon write
Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Zbigniew Jasinskiauthored and Casey Schauflercommited 2015-10-19 12:06:47 -07:00
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.
So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphalauthored and Pablo Neira Ayusocommited 2015-10-16 18:21:39 +02:00
This fix writes the task label when
smack_d_instantiate is called, before the
label of the superblock was written on the
pipe's inode.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Roman Kubiakauthored and Casey Schauflercommited 2015-10-09 15:13:41 -07:00
This change has two goals:
- delay the setting of 'smack_enabled' until
it will be really effective
- ensure that smackfs is valid only if 'smack_enabled'
is set (it is already the case in smack_netfilter.c)
Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
José Bolloauthored and Casey Schauflercommited 2015-10-09 15:13:24 -07:00
Fixes the following sparse warning:
security/smack/smack_lsm.c:55:1: warning: symbol 'smk_ipv6_port_list'
was not declared. Should it be static?
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Geliang Tangauthored and Casey Schauflercommited 2015-10-09 15:13:08 -07:00
'commit e774ad683f ("smack: pass error code through pointers")'
made this function return proper error codes instead of NULL. Reflect that.
This is a fix for a NULL dereference introduced in
'commit 21abb1ec41 ("Smack: IPv6 host labeling")'
echo "$SOME_IPV6_ADDR \"test" > /smack/ipv6host
(this should return EINVAL, it doesn't)
cat /smack/ipv6host
(derefences 0x000a)
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Lukasz Pawelczykauthored and Casey Schauflercommited 2015-10-09 15:12:46 -07:00
Only pass the void *priv parameter out of the nf_hook_ops. That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Eric W. Biedermanauthored and Pablo Neira Ayusocommited 2015-09-18 22:00:16 +02:00
The changes for mounting binary filesystems was allied
improperly, with the list of tokens being in an ifdef that
it shouldn't have been. Fix that, and a couple style issues
that were bothering me.
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Adds an ignore case for kernel tasks,
so that they can access all resources.
Since kernel worker threads are spawned with
floor label, they are severely restricted by
Smack policy. It is not an issue without onlycap,
as these processes also run with root,
so CAP_MAC_OVERRIDE kicks in. But with onlycap
turned on, there is no way to change the label
for these processes.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Roman Kubiakauthored and Casey Schauflercommited 2015-08-10 15:15:50 -07:00
The kbuild test robot reported a couple of these,
and the third showed up by inspection. Making the
symbols static is proper.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
IPv6 appears to be (finally) coming of age with the
influx of autonomous devices. In support of this, add
the ability to associate a Smack label with IPv6 addresses.
This patch also cleans up some of the conditional
compilation associated with the introduction of
secmark processing. It's now more obvious which bit
of code goes with which feature.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
security/smack/smackfs.c:2251:1-4: WARNING: end returns can be
simpified and declaration on line 2250 can be dropped
Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
kbuild test robotauthored and Casey Schauflercommited 2015-07-22 12:31:40 -07:00
Add support for setting smack mount labels(using smackfsdef, smackfsroot,
smackfshat, smackfsfloor, smackfstransmute) for filesystems with binary
mount data like NFS.
To achieve this, implement sb_parse_opts_str and sb_set_mnt_opts security
operations in smack LSM similar to SELinux.
Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Vivek Trivediauthored and Casey Schauflercommited 2015-07-22 12:31:28 -07:00
Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.
Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.
There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.
This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.
This set of changes also addresses an issue with how open file
descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of
/proc/<pid>/fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.
There is also a short list of issues that have not been fixed yet that
I will mention briefly.
It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.
As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
Kyle Yan
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Casey Schaufler
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Greg Kroah-Hartman
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James Morris
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Olav Haugan
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Linus Torvalds
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Andreas Gruenbacher
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Al Viro
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James Morris
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Markus Elfring
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Javier Martinez Canillas
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Paul Moore
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José Bollo
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Jann Horn
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Paul Moore
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Roman Kubiak
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Eric Dumazet
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David S. Miller
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Florian Westphal
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Pablo Neira Ayuso
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Geliang Tang
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kbuild test robot
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Vivek Trivedi
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