Commit Graph

5015 Commits

Author SHA1 Message Date
Stephen Kitt
53944f171a mm: remove HARDENED_USERCOPY_FALLBACK
This has served its purpose and is no longer used.  All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.

This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.

This also removes the usercopy_fallback module parameter on slab_common.

Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>	[defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Linus Torvalds
9d235ac01f Merge branch 'ucount-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucounts fixes from Eric Biederman:
 "There has been one very hard to track down bug in the ucount code that
  we have been tracking since roughly v5.14 was released. Alex managed
  to find a reliable reproducer a few days ago and then I was able to
  instrument the code and figure out what the issue was.

  It turns out the sigqueue_alloc single atomic operation optimization
  did not play nicely with ucounts multiple level rlimits. It turned out
  that either sigqueue_alloc or sigqueue_free could be operating on
  multiple levels and trigger the conditions for the optimization on
  more than one level at the same time.

  To deal with that situation I have introduced inc_rlimit_get_ucounts
  and dec_rlimit_put_ucounts that just focuses on the optimization and
  the rlimit and ucount changes.

  While looking into the big bug I found I couple of other little issues
  so I am including those fixes here as well.

  When I have time I would very much like to dig into process ownership
  of the shared signal queue and see if we could pick a single owner for
  the entire queue so that all of the rlimits can count to that owner.
  That should entirely remove the need to call get_ucounts and
  put_ucounts in sigqueue_alloc and sigqueue_free. It is difficult
  because Linux unlike POSIX supports setuid that works on a single
  thread"

* 'ucount-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: Move get_ucounts from cred_alloc_blank to key_change_session_keyring
  ucounts: Proper error handling in set_cred_ucounts
  ucounts: Pair inc_rlimit_ucounts with dec_rlimit_ucoutns in commit_creds
  ucounts: Fix signal ucount refcounting
2021-10-21 17:27:17 -10:00
Eric W. Biederman
5ebcbe342b ucounts: Move get_ucounts from cred_alloc_blank to key_change_session_keyring
Setting cred->ucounts in cred_alloc_blank does not make sense.  The
uid and user_ns are deliberately not set in cred_alloc_blank but
instead the setting is delayed until key_change_session_keyring.

So move dealing with ucounts into key_change_session_keyring as well.

Unfortunately that movement of get_ucounts adds a new failure mode to
key_change_session_keyring.  I do not see anything stopping the parent
process from calling setuid and changing the relevant part of it's
cred while keyctl_session_to_parent is running making it fundamentally
necessary to call get_ucounts in key_change_session_keyring.  Which
means that the new failure mode cannot be avoided.

A failure of key_change_session_keyring results in a single threaded
parent keeping it's existing credentials.  Which results in the parent
process not being able to access the session keyring and whichever
keys are in the new keyring.

Further get_ucounts is only expected to fail if the number of bits in
the refernece count for the structure is too few.

Since the code has no other way to report the failure of get_ucounts
and because such failures are not expected to be common add a WARN_ONCE
to report this problem to userspace.

Between the WARN_ONCE and the parent process not having access to
the keys in the new session keyring I expect any failure of get_ucounts
will be noticed and reported and we can find another way to handle this
condition.  (Possibly by just making ucounts->count an atomic_long_t).

Cc: stable@vger.kernel.org
Fixes: 905ae01c4a ("Add a reference to ucounts for each cred")
Link: https://lkml.kernel.org/r/7k0ias0uf.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-20 10:34:20 -05:00
David S. Miller
578f393227 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/
ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2021-10-07

1) Fix a sysbot reported shift-out-of-bounds in xfrm_get_default.
   From Pavel Skripkin.

2) Fix XFRM_MSG_MAPPING ABI breakage. The new XFRM_MSG_MAPPING
   messages were accidentally not paced at the end.
   Fix by Eugene Syromiatnikov.

3) Fix the uapi for the default policy, use explicit field and macros
   and make it accessible to userland.
   From Nicolas Dichtel.

4) Fix a missing rcu lock in xfrm_notify_userpolicy().
   From Nicolas Dichtel.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-07 12:44:41 +01:00
Paul Moore
a3727a8bac selinux,smack: fix subjective/objective credential use mixups
Jann Horn reported a problem with commit eb1231f73c ("selinux:
clarify task subjective and objective credentials") where some LSM
hooks were attempting to access the subjective credentials of a task
other than the current task.  Generally speaking, it is not safe to
access another task's subjective credentials and doing so can cause
a number of problems.

Further, while looking into the problem, I realized that Smack was
suffering from a similar problem brought about by a similar commit
1fb057dcde ("smack: differentiate between subjective and objective
task credentials").

This patch addresses this problem by restoring the use of the task's
objective credentials in those cases where the task is other than the
current executing task.  Not only does this resolve the problem
reported by Jann, it is arguably the correct thing to do in these
cases.

Cc: stable@vger.kernel.org
Fixes: eb1231f73c ("selinux: clarify task subjective and objective credentials")
Fixes: 1fb057dcde ("smack: differentiate between subjective and objective task credentials")
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-23 12:30:59 -04:00
Eugene Syromiatnikov
844f7eaaed include/uapi/linux/xfrm.h: Fix XFRM_MSG_MAPPING ABI breakage
Commit 2d151d3907 ("xfrm: Add possibility to set the default to block
if we have no policy") broke ABI by changing the value of the XFRM_MSG_MAPPING
enum item, thus also evading the build-time check
in security/selinux/nlmsgtab.c:selinux_nlmsg_lookup for presence of proper
security permission checks in nlmsg_xfrm_perms.  Fix it by placing
XFRM_MSG_SETDEFAULT/XFRM_MSG_GETDEFAULT to the end of the enum, right before
__XFRM_MSG_MAX, and updating the nlmsg_xfrm_perms accordingly.

Fixes: 2d151d3907 ("xfrm: Add possibility to set the default to block if we have no policy")
References: https://lore.kernel.org/netdev/20210901151402.GA2557@altlinux.org/
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Acked-by: Antony Antony <antony.antony@secunet.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2021-09-14 10:31:35 +02:00
Linus Torvalds
b250e6d141 Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
2021-09-03 15:33:47 -07:00
Linus Torvalds
14726903c8 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
2021-09-03 10:08:28 -07:00
Luigi Rizzo
5b78ed24e8 mm/pagemap: add mmap_assert_locked() annotations to find_vma*()
find_vma() and variants need protection when used.  This patch adds
mmap_assert_lock() calls in the functions.

To make sure the invariant is satisfied, we also need to add a
mmap_read_lock() around the get_user_pages_remote() call in
get_arg_page().  The lock is not strictly necessary because the mm has
been newly created, but the extra cost is limited because the same mutex
was also acquired shortly before in __bprm_mm_init(), so it is hot and
uncontended.

[penguin-kernel@i-love.sakura.ne.jp: TOMOYO needs the same protection which get_arg_page() needs]
  Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp

Link: https://lkml.kernel.org/r/20210731175341.3458608-1-lrizzo@google.com
Signed-off-by: Luigi Rizzo <lrizzo@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:13 -07:00
Masahiro Yamada
e052826ff1 security: remove unneeded subdir-$(CONFIG_...)
All of these are unneeded. The directories to descend are specified
by obj-$(CONFIG_...).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-09-03 08:17:20 +09:00
Linus Torvalds
aef4892a63 Merge tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity subsystem updates from Mimi Zohar:

 - Limit the allowed hash algorithms when writing security.ima xattrs or
   verifying them, based on the IMA policy and the configured hash
   algorithms.

 - Return the calculated "critical data" measurement hash and size to
   avoid code duplication. (Preparatory change for a proposed LSM.)

 - and a single patch to address a compiler warning.

* tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  IMA: reject unknown hash algorithms in ima_get_hash_algo
  IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms
  IMA: introduce a new policy option func=SETXATTR_CHECK
  IMA: add a policy option to restrict xattr hash algorithms on appraisal
  IMA: add support to restrict the hash algorithms used for file appraisal
  IMA: block writes of the security.ima xattr with unsupported algorithms
  IMA: remove the dependency on CRYPTO_MD5
  ima: Add digest and digest_len params to the functions to measure a buffer
  ima: Return int in the functions to measure a buffer
  ima: Introduce ima_get_current_hash_algo()
  IMA: remove -Wmissing-prototypes warning
2021-09-02 12:51:41 -07:00
Linus Torvalds
b55060d796 Merge tag 'hardening-v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:

 - Expand lib/test_stackinit to include more initialization styles

 - Improve Kconfig for CLang's auto-var-init feature

 - Introduce support for GCC's zero-call-used-regs feature

* tag 'hardening-v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib/test_stackinit: Add assigned initializers
  lib/test_stackinit: Allow building stand-alone
  lib/test_stackinit: Fix static initializer test
  hardening: Clarify Kconfig text for auto-var-init
  hardening: Introduce CONFIG_ZERO_CALL_USED_REGS
2021-09-02 12:35:34 -07:00
Linus Torvalds
9e9fb7655e Merge tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
 "Core:

   - Enable memcg accounting for various networking objects.

  BPF:

   - Introduce bpf timers.

   - Add perf link and opaque bpf_cookie which the program can read out
     again, to be used in libbpf-based USDT library.

   - Add bpf_task_pt_regs() helper to access user space pt_regs in
     kprobes, to help user space stack unwinding.

   - Add support for UNIX sockets for BPF sockmap.

   - Extend BPF iterator support for UNIX domain sockets.

   - Allow BPF TCP congestion control progs and bpf iterators to call
     bpf_setsockopt(), e.g. to switch to another congestion control
     algorithm.

  Protocols:

   - Support IOAM Pre-allocated Trace with IPv6.

   - Support Management Component Transport Protocol.

   - bridge: multicast: add vlan support.

   - netfilter: add hooks for the SRv6 lightweight tunnel driver.

   - tcp:
       - enable mid-stream window clamping (by user space or BPF)
       - allow data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
       - more accurate DSACK processing for RACK-TLP

   - mptcp:
       - add full mesh path manager option
       - add partial support for MP_FAIL
       - improve use of backup subflows
       - optimize option processing

   - af_unix: add OOB notification support.

   - ipv6: add IFLA_INET6_RA_MTU to expose MTU value advertised by the
     router.

   - mac80211: Target Wake Time support in AP mode.

   - can: j1939: extend UAPI to notify about RX status.

  Driver APIs:

   - Add page frag support in page pool API.

   - Many improvements to the DSA (distributed switch) APIs.

   - ethtool: extend IRQ coalesce uAPI with timer reset modes.

   - devlink: control which auxiliary devices are created.

   - Support CAN PHYs via the generic PHY subsystem.

   - Proper cross-chip support for tag_8021q.

   - Allow TX forwarding for the software bridge data path to be
     offloaded to capable devices.

  Drivers:

   - veth: more flexible channels number configuration.

   - openvswitch: introduce per-cpu upcall dispatch.

   - Add internet mix (IMIX) mode to pktgen.

   - Transparently handle XDP operations in the bonding driver.

   - Add LiteETH network driver.

   - Renesas (ravb):
       - support Gigabit Ethernet IP

   - NXP Ethernet switch (sja1105):
       - fast aging support
       - support for "H" switch topologies
       - traffic termination for ports under VLAN-aware bridge

   - Intel 1G Ethernet
       - support getcrosststamp() with PCIe PTM (Precision Time
         Measurement) for better time sync
       - support Credit-Based Shaper (CBS) offload, enabling HW traffic
         prioritization and bandwidth reservation

   - Broadcom Ethernet (bnxt)
       - support pulse-per-second output
       - support larger Rx rings

   - Mellanox Ethernet (mlx5)
       - support ethtool RSS contexts and MQPRIO channel mode
       - support LAG offload with bridging
       - support devlink rate limit API
       - support packet sampling on tunnels

   - Huawei Ethernet (hns3):
       - basic devlink support
       - add extended IRQ coalescing support
       - report extended link state

   - Netronome Ethernet (nfp):
       - add conntrack offload support

   - Broadcom WiFi (brcmfmac):
       - add WPA3 Personal with FT to supported cipher suites
       - support 43752 SDIO device

   - Intel WiFi (iwlwifi):
       - support scanning hidden 6GHz networks
       - support for a new hardware family (Bz)

   - Xen pv driver:
       - harden netfront against malicious backends

   - Qualcomm mobile
       - ipa: refactor power management and enable automatic suspend
       - mhi: move MBIM to WWAN subsystem interfaces

  Refactor:

   - Ambient BPF run context and cgroup storage cleanup.

   - Compat rework for ndo_ioctl.

  Old code removal:

   - prism54 remove the obsoleted driver, deprecated by the p54 driver.

   - wan: remove sbni/granch driver"

* tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1715 commits)
  net: Add depends on OF_NET for LiteX's LiteETH
  ipv6: seg6: remove duplicated include
  net: hns3: remove unnecessary spaces
  net: hns3: add some required spaces
  net: hns3: clean up a type mismatch warning
  net: hns3: refine function hns3_set_default_feature()
  ipv6: remove duplicated 'net/lwtunnel.h' include
  net: w5100: check return value after calling platform_get_resource()
  net/mlxbf_gige: Make use of devm_platform_ioremap_resourcexxx()
  net: mdio: mscc-miim: Make use of the helper function devm_platform_ioremap_resource()
  net: mdio-ipq4019: Make use of devm_platform_ioremap_resource()
  fou: remove sparse errors
  ipv4: fix endianness issue in inet_rtm_getroute_build_skb()
  octeontx2-af: Set proper errorcode for IPv4 checksum errors
  octeontx2-af: Fix static code analyzer reported issues
  octeontx2-af: Fix mailbox errors in nix_rss_flowkey_cfg
  octeontx2-af: Fix loop in free and unmap counter
  af_unix: fix potential NULL deref in unix_dgram_connect()
  dpaa2-eth: Replace strlcpy with strscpy
  octeontx2-af: Use NDC TX for transmit packet data
  ...
2021-08-31 16:43:06 -07:00
Linus Torvalds
efa916af13 Merge tag 'for-5.15/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:

 - Add DM infrastructure for IMA-based remote attestion. These changes
   are the basis for deploying DM-based storage in a "cloud" that must
   validate configurations end-users run to maintain trust. These DM
   changes allow supported DM targets' configurations to be measured via
   IMA. But the policy and enforcement (of which configurations are
   valid) is managed by something outside the kernel (e.g. Keylime).

 - Fix DM crypt scalability regression on systems with many cpus due to
   percpu_counter spinlock contention in crypt_page_alloc().

 - Use in_hardirq() instead of deprecated in_irq() in DM crypt.

 - Add event counters to DM writecache to allow users to further assess
   how the writecache is performing.

 - Various code cleanup in DM writecache's main IO mapping function.

* tag 'for-5.15/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: use in_hardirq() instead of deprecated in_irq()
  dm ima: update dm documentation for ima measurement support
  dm ima: update dm target attributes for ima measurements
  dm ima: add a warning in dm_init if duplicate ima events are not measured
  dm ima: prefix ima event name related to device mapper with dm_
  dm ima: add version info to dm related events in ima log
  dm ima: prefix dm table hashes in ima log with hash algorithm
  dm crypt: Avoid percpu_counter spinlock contention in crypt_page_alloc()
  dm: add documentation for IMA measurement support
  dm: update target status functions to support IMA measurement
  dm ima: measure data on device rename
  dm ima: measure data on table clear
  dm ima: measure data on device remove
  dm ima: measure data on device resume
  dm ima: measure data on table load
  dm writecache: add event counters
  dm writecache: report invalid return from writecache_map helpers
  dm writecache: further writecache_map() cleanup
  dm writecache: factor out writecache_map_remap_origin()
  dm writecache: split up writecache_map() to improve code readability
2021-08-31 14:55:09 -07:00
Linus Torvalds
9b2eacd8f0 Merge tag 'Smack-for-5.15' of git://github.com/cschaufler/smack-next
Pull smack updates from Casey Schaufler:
 "There is a variable used only during start-up that's now marked
  __initdata and a change where the code was working by sheer luck that
  is now done properly.

  Both have been in next for several weeks and pass the Smack testsuite"

* tag 'Smack-for-5.15' of git://github.com/cschaufler/smack-next:
  smack: mark 'smack_enabled' global variable as __initdata
  Smack: Fix wrong semantics in smk_access_entry()
2021-08-31 13:01:40 -07:00
Linus Torvalds
befa491ce6 Merge tag 'selinux-pr-20210830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux update from Paul Moore:
 "We've got an unusually small SELinux pull request for v5.15 that
  consists of only one (?!) patch that is really pretty minor when you
  look at it.

  Unsurprisingly it passes all of our tests and merges cleanly on top of
  your tree right now, please merge this for v5.15"

* tag 'selinux-pr-20210830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: return early for possible NULL audit buffers
2021-08-31 12:53:34 -07:00
Linus Torvalds
46f4945e2b Merge tag 'efi-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
 "A handful of EFI changes for this cycle:

   - EFI CPER parsing improvements

   - Don't take the address of efi_guid_t internal fields"

* tag 'efi-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: cper: check section header more appropriately
  efi: Don't use knowledge about efi_guid_t internals
  efi: cper: fix scnprintf() use in cper_mem_err_location()
2021-08-30 13:57:55 -07:00
Andy Shevchenko
b31eea2e04 efi: Don't use knowledge about efi_guid_t internals
When print GUIDs supply pointer to the efi_guid_t (guid_t) type rather
its internal members.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-08-27 16:01:27 +02:00
THOBY Simon
cb181da161 IMA: reject unknown hash algorithms in ima_get_hash_algo
The new function validate_hash_algo() assumed that ima_get_hash_algo()
always return a valid 'enum hash_algo', but it returned the
user-supplied value present in the digital signature without
any bounds checks.

Update ima_get_hash_algo() to always return a valid hash algorithm,
defaulting on 'ima_hash_algo' when the user-supplied value inside
the xattr is invalid.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reported-by: syzbot+e8bafe7b82c739eaf153@syzkaller.appspotmail.com
Fixes: 50f742dd91 ("IMA: block writes of the security.ima xattr with unsupported algorithms")
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-23 18:22:00 -04:00
THOBY Simon
8ecd39cb61 IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms
SETXATTR_CHECK policy rules assume that any algorithm listed in the
'appraise_algos' flag must be accepted when performing setxattr() on
the security.ima xattr.  However nothing checks that they are
available in the current kernel.  A userland application could hash
a file with a digest that the kernel wouldn't be able to verify.
However, if SETXATTR_CHECK is not in use, the kernel already forbids
that xattr write.

Verify that algorithms listed in appraise_algos are available to the
current kernel and reject the policy update otherwise. This will fix
the inconsistency between SETXATTR_CHECK and non-SETXATTR_CHECK
behaviors.

That filtering is only performed in ima_parse_appraise_algos() when
updating policies so that we do not have to pay the price of
allocating a hash object every time validate_hash_algo() is called
in ima_inode_setxattr().

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:35:35 -04:00
THOBY Simon
4f2946aa0c IMA: introduce a new policy option func=SETXATTR_CHECK
While users can restrict the accepted hash algorithms for the
security.ima xattr file signature when appraising said file, users
cannot restrict the algorithms that can be set on that attribute:
any algorithm built in the kernel is accepted on a write.

Define a new value for the ima policy option 'func' that restricts
globally the hash algorithms accepted when writing the security.ima
xattr.

When a policy contains a rule of the form
	appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512
only values corresponding to one of these three digest algorithms
will be accepted for writing the security.ima xattr.  Attempting to
write the attribute using another algorithm (or "free-form" data)
will be denied with an audit log message.  In the absence of such a
policy rule, the default is still to only accept hash algorithms
built in the kernel (with all the limitations that entails).

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:35:35 -04:00
THOBY Simon
583a80ae86 IMA: add a policy option to restrict xattr hash algorithms on appraisal
The kernel has the ability to restrict the set of hash algorithms it
accepts for the security.ima xattr when it appraises files.

Define a new IMA policy rule option "appraise_algos=", using the
mentioned mechanism to expose a user-toggable policy knob to opt-in
to that restriction and select the desired set of algorithms that
must be accepted.

When a policy rule uses the 'appraise_algos' option, appraisal of a
file referenced by that rule will now fail if the digest algorithm
employed to hash the file was not one of those explicitly listed in
the option.  In its absence, any hash algorithm compiled in the
kernel will be accepted.

For example, on a system where SELinux is properly deployed, the rule
	appraise func=BPRM_CHECK obj_type=iptables_exec_t \
		appraise_algos=sha256,sha384
will block the execution of iptables if the xattr security.ima of its
executables were not hashed with either sha256 or sha384.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:33:07 -04:00
THOBY Simon
1624dc0086 IMA: add support to restrict the hash algorithms used for file appraisal
The kernel accepts any hash algorithm as a value for the security.ima
xattr. Users may wish to restrict the accepted algorithms to only
support strong cryptographic ones.

Provide the plumbing to restrict the permitted set of hash algorithms
used for verifying file hashes and signatures stored in security.ima
xattr.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:30:41 -04:00
THOBY Simon
50f742dd91 IMA: block writes of the security.ima xattr with unsupported algorithms
By default, writes to the extended attributes security.ima will be
allowed even if the hash algorithm used for the xattr is not compiled
in the kernel (which does not make sense because the kernel would not
be able to appraise that file as it lacks support for validating the
hash).

Prevent and audit writes to the security.ima xattr if the hash algorithm
used in the new value is not available in the current kernel.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:30:41 -04:00
THOBY Simon
8510505d55 IMA: remove the dependency on CRYPTO_MD5
MD5 is a weak digest algorithm that shouldn't be used for cryptographic
operation. It hinders the efficiency of a patch set that aims to limit
the digests allowed for the extended file attribute namely security.ima.
MD5 is no longer a requirement for IMA, nor should it be used there.

The sole place where we still use the MD5 algorithm inside IMA is setting
the ima_hash algorithm to MD5, if the user supplies 'ima_hash=md5'
parameter on the command line.  With commit ab60368ab6 ("ima: Fallback
to the builtin hash algorithm"), setting "ima_hash=md5" fails gracefully
when CRYPTO_MD5 is not set:
	ima: Can not allocate md5 (reason: -2)
	ima: Allocating md5 failed, going to use default hash algorithm sha256

Remove the CRYPTO_MD5 dependency for IMA.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
[zohar@linux.ibm.com: include commit number in patch description for
stable.]
Cc: stable@vger.kernel.org # 4.17
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:29:10 -04:00