<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/testing, branch v6.0-rc5</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'net-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-09-08T12:15:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-09-08T12:15:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=26b1224903b3fb66e8aa564868d0d57648c32b15'/>
<id>26b1224903b3fb66e8aa564868d0d57648c32b15</id>
<content type='text'>
Pull networking fixes from Paolo Abeni:
 "Including fixes from rxrpc, netfilter, wireless and bluetooth
  subtrees.

  Current release - regressions:

   - skb: export skb drop reaons to user by TRACE_DEFINE_ENUM

   - bluetooth: fix regression preventing ACL packet transmission

  Current release - new code bugs:

   - dsa: microchip: fix kernel oops on ksz8 switches

   - dsa: qca8k: fix NULL pointer dereference for
     of_device_get_match_data

  Previous releases - regressions:

   - netfilter: clean up hook list when offload flags check fails

   - wifi: mt76: fix crash in chip reset fail

   - rxrpc: fix ICMP/ICMP6 error handling

   - ice: fix DMA mappings leak

   - i40e: fix kernel crash during module removal

  Previous releases - always broken:

   - ipv6: sr: fix out-of-bounds read when setting HMAC data.

   - tcp: TX zerocopy should not sense pfmemalloc status

   - sch_sfb: don't assume the skb is still around after
     enqueueing to child

   - netfilter: drop dst references before setting

   - wifi: wilc1000: fix DMA on stack objects

   - rxrpc: fix an insufficiently large sglist in
     rxkad_verify_packet_2()

   - fec: use a spinlock to guard `fep-&gt;ptp_clk_on`

  Misc:

   - usb: qmi_wwan: add Quectel RM520N"

* tag 'net-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (50 commits)
  sch_sfb: Also store skb len before calling child enqueue
  net: phy: lan87xx: change interrupt src of link_up to comm_ready
  net/smc: Fix possible access to freed memory in link clear
  net: ethernet: mtk_eth_soc: check max allowed hash in mtk_ppe_check_skb
  net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM
  net: ethernet: mtk_eth_soc: fix typo in __mtk_foe_entry_clear
  net: dsa: felix: access QSYS_TAG_CONFIG under tas_lock in vsc9959_sched_speed_set
  net: dsa: felix: disable cut-through forwarding for frames oversized for tc-taprio
  net: dsa: felix: tc-taprio intervals smaller than MTU should send at least one packet
  net: usb: qmi_wwan: add Quectel RM520N
  net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data
  tcp: fix early ETIMEDOUT after spurious non-SACK RTO
  stmmac: intel: Simplify intel_eth_pci_remove()
  net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()
  ipv6: sr: fix out-of-bounds read when setting HMAC data.
  bonding: accept unsolicited NA message
  bonding: add all node mcast address when slave up
  bonding: use unspecified address if no available link local address
  wifi: use struct_group to copy addresses
  wifi: mac80211_hwsim: check length for virtio packets
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from Paolo Abeni:
 "Including fixes from rxrpc, netfilter, wireless and bluetooth
  subtrees.

  Current release - regressions:

   - skb: export skb drop reaons to user by TRACE_DEFINE_ENUM

   - bluetooth: fix regression preventing ACL packet transmission

  Current release - new code bugs:

   - dsa: microchip: fix kernel oops on ksz8 switches

   - dsa: qca8k: fix NULL pointer dereference for
     of_device_get_match_data

  Previous releases - regressions:

   - netfilter: clean up hook list when offload flags check fails

   - wifi: mt76: fix crash in chip reset fail

   - rxrpc: fix ICMP/ICMP6 error handling

   - ice: fix DMA mappings leak

   - i40e: fix kernel crash during module removal

  Previous releases - always broken:

   - ipv6: sr: fix out-of-bounds read when setting HMAC data.

   - tcp: TX zerocopy should not sense pfmemalloc status

   - sch_sfb: don't assume the skb is still around after
     enqueueing to child

   - netfilter: drop dst references before setting

   - wifi: wilc1000: fix DMA on stack objects

   - rxrpc: fix an insufficiently large sglist in
     rxkad_verify_packet_2()

   - fec: use a spinlock to guard `fep-&gt;ptp_clk_on`

  Misc:

   - usb: qmi_wwan: add Quectel RM520N"

* tag 'net-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (50 commits)
  sch_sfb: Also store skb len before calling child enqueue
  net: phy: lan87xx: change interrupt src of link_up to comm_ready
  net/smc: Fix possible access to freed memory in link clear
  net: ethernet: mtk_eth_soc: check max allowed hash in mtk_ppe_check_skb
  net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM
  net: ethernet: mtk_eth_soc: fix typo in __mtk_foe_entry_clear
  net: dsa: felix: access QSYS_TAG_CONFIG under tas_lock in vsc9959_sched_speed_set
  net: dsa: felix: disable cut-through forwarding for frames oversized for tc-taprio
  net: dsa: felix: tc-taprio intervals smaller than MTU should send at least one packet
  net: usb: qmi_wwan: add Quectel RM520N
  net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data
  tcp: fix early ETIMEDOUT after spurious non-SACK RTO
  stmmac: intel: Simplify intel_eth_pci_remove()
  net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()
  ipv6: sr: fix out-of-bounds read when setting HMAC data.
  bonding: accept unsolicited NA message
  bonding: add all node mcast address when slave up
  bonding: use unspecified address if no available link local address
  wifi: use struct_group to copy addresses
  wifi: mac80211_hwsim: check length for virtio packets
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-09-04T18:27:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-09-04T18:27:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=685ed983e2dc330680a076a1fd37ebe04017df91'/>
<id>685ed983e2dc330680a076a1fd37ebe04017df91</id>
<content type='text'>
Pull kvm fixes from Paolo Bonzini:
 "s390:

   - PCI interpretation compile fixes

  RISC-V:

   - fix unused variable warnings in vcpu_timer.c

   - move extern sbi_ext declarations to a header

  x86:

   - check validity of argument to KVM_SET_MP_STATE

   - use guest's global_ctrl to completely disable guest PEBS

   - fix a memory leak on memory allocation failure

   - mask off unsupported and unknown bits of IA32_ARCH_CAPABILITIES

   - fix build failure with Clang integrated assembler

   - fix MSR interception

   - always flush TLBs when enabling dirty logging"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: check validity of argument to KVM_SET_MP_STATE
  perf/x86/core: Completely disable guest PEBS via guest's global_ctrl
  KVM: x86: fix memoryleak in kvm_arch_vcpu_create()
  KVM: x86: Mask off unsupported and unknown bits of IA32_ARCH_CAPABILITIES
  KVM: s390: pci: Hook to access KVM lowlevel from VFIO
  riscv: kvm: move extern sbi_ext declarations to a header
  riscv: kvm: vcpu_timer: fix unused variable warnings
  KVM: selftests: Fix ambiguous mov in KVM_ASM_SAFE()
  KVM: selftests: Fix KVM_EXCEPTION_MAGIC build with Clang
  KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()
  kvm: x86: mmu: Always flush TLBs when enabling dirty logging
  kvm: x86: mmu: Drop the need_remote_flush() function
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kvm fixes from Paolo Bonzini:
 "s390:

   - PCI interpretation compile fixes

  RISC-V:

   - fix unused variable warnings in vcpu_timer.c

   - move extern sbi_ext declarations to a header

  x86:

   - check validity of argument to KVM_SET_MP_STATE

   - use guest's global_ctrl to completely disable guest PEBS

   - fix a memory leak on memory allocation failure

   - mask off unsupported and unknown bits of IA32_ARCH_CAPABILITIES

   - fix build failure with Clang integrated assembler

   - fix MSR interception

   - always flush TLBs when enabling dirty logging"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: check validity of argument to KVM_SET_MP_STATE
  perf/x86/core: Completely disable guest PEBS via guest's global_ctrl
  KVM: x86: fix memoryleak in kvm_arch_vcpu_create()
  KVM: x86: Mask off unsupported and unknown bits of IA32_ARCH_CAPABILITIES
  KVM: s390: pci: Hook to access KVM lowlevel from VFIO
  riscv: kvm: move extern sbi_ext declarations to a header
  riscv: kvm: vcpu_timer: fix unused variable warnings
  KVM: selftests: Fix ambiguous mov in KVM_ASM_SAFE()
  KVM: selftests: Fix KVM_EXCEPTION_MAGIC build with Clang
  KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()
  kvm: x86: mmu: Always flush TLBs when enabling dirty logging
  kvm: x86: mmu: Drop the need_remote_flush() function
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf</title>
<updated>2022-09-03T02:38:25+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-09-03T02:38:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=05a5474efe93054893f1a7936398381e23ecea60'/>
<id>05a5474efe93054893f1a7936398381e23ecea60</id>
<content type='text'>
Florian Westphal says:

====================
netfilter: bug fixes for net

1. Fix IP address check in irc DCC conntrack helper, this should check
   the opposite direction rather than the destination address of the
   packets' direction, from David Leadbeater.

2. bridge netfilter needs to drop dst references, from Harsh Modi.
   This was fine back in the day the code was originally written,
   but nowadays various tunnels can pre-set metadata dsts on packets.

3. Remove nf_conntrack_helper sysctl and the modparam toggle, users
   need to explicitily assign the helpers to use via nftables or
   iptables.  Conntrack helpers, by design, may be used to add dynamic
   port redirections to internal machines, so its necessary to restrict
   which hosts/peers are allowed to use them.
   It was discovered that improper checking in the irc DCC helper makes
   it possible to trigger the 'please do dynamic port forward'
   from outside by embedding a 'DCC' in a PING request; if the client
   echos that back a expectation/port forward gets added.
   The auto-assign-for-everything mechanism has been in "please don't do this"
   territory since 2012.  From Pablo.

4. Fix a memory leak in the netdev hook error unwind path, also from Pablo.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_conntrack_irc: Fix forged IP logic
  netfilter: nf_tables: clean up hook list when offload flags check fails
  netfilter: br_netfilter: Drop dst references before setting.
  netfilter: remove nf_conntrack_helper sysctl and modparam toggles
====================

Link: https://lore.kernel.org/r/20220901071238.3044-1-fw@strlen.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Florian Westphal says:

====================
netfilter: bug fixes for net

1. Fix IP address check in irc DCC conntrack helper, this should check
   the opposite direction rather than the destination address of the
   packets' direction, from David Leadbeater.

2. bridge netfilter needs to drop dst references, from Harsh Modi.
   This was fine back in the day the code was originally written,
   but nowadays various tunnels can pre-set metadata dsts on packets.

3. Remove nf_conntrack_helper sysctl and the modparam toggle, users
   need to explicitily assign the helpers to use via nftables or
   iptables.  Conntrack helpers, by design, may be used to add dynamic
   port redirections to internal machines, so its necessary to restrict
   which hosts/peers are allowed to use them.
   It was discovered that improper checking in the irc DCC helper makes
   it possible to trigger the 'please do dynamic port forward'
   from outside by embedding a 'DCC' in a PING request; if the client
   echos that back a expectation/port forward gets added.
   The auto-assign-for-everything mechanism has been in "please don't do this"
   territory since 2012.  From Pablo.

4. Fix a memory leak in the netdev hook error unwind path, also from Pablo.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_conntrack_irc: Fix forged IP logic
  netfilter: nf_tables: clean up hook list when offload flags check fails
  netfilter: br_netfilter: Drop dst references before setting.
  netfilter: remove nf_conntrack_helper sysctl and modparam toggles
====================

Link: https://lore.kernel.org/r/20220901071238.3044-1-fw@strlen.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'io_uring-6.0-2022-09-02' of git://git.kernel.dk/linux-block</title>
<updated>2022-09-02T23:37:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-09-02T23:37:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cec53f4c8df0b3f45796127a31c10b86ec125f55'/>
<id>cec53f4c8df0b3f45796127a31c10b86ec125f55</id>
<content type='text'>
Pull io_uring fixes from Jens Axboe:

 - A single fix for over-eager retries for networking (Pavel)

 - Revert the notification slot support for zerocopy sends.

   It turns out that even after more than a year or development and
   testing, there's not full agreement on whether just using plain
   ordered notifications is Good Enough to avoid the complexity of using
   the notifications slots. Because of that, we decided that it's best
   left to a future final decision.

   We can always bring back this feature, but we can't really change it
   or remove it once we've released 6.0 with it enabled. The reverts
   leave the usual CQE notifications as the primary interface for
   knowing when data was sent, and when it was acked. (Pavel)

* tag 'io_uring-6.0-2022-09-02' of git://git.kernel.dk/linux-block:
  selftests/net: return back io_uring zc send tests
  io_uring/net: simplify zerocopy send user API
  io_uring/notif: remove notif registration
  Revert "io_uring: rename IORING_OP_FILES_UPDATE"
  Revert "io_uring: add zc notification flush requests"
  selftests/net: temporarily disable io_uring zc test
  io_uring/net: fix overexcessive retries
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull io_uring fixes from Jens Axboe:

 - A single fix for over-eager retries for networking (Pavel)

 - Revert the notification slot support for zerocopy sends.

   It turns out that even after more than a year or development and
   testing, there's not full agreement on whether just using plain
   ordered notifications is Good Enough to avoid the complexity of using
   the notifications slots. Because of that, we decided that it's best
   left to a future final decision.

   We can always bring back this feature, but we can't really change it
   or remove it once we've released 6.0 with it enabled. The reverts
   leave the usual CQE notifications as the primary interface for
   knowing when data was sent, and when it was acked. (Pavel)

* tag 'io_uring-6.0-2022-09-02' of git://git.kernel.dk/linux-block:
  selftests/net: return back io_uring zc send tests
  io_uring/net: simplify zerocopy send user API
  io_uring/notif: remove notif registration
  Revert "io_uring: rename IORING_OP_FILES_UPDATE"
  Revert "io_uring: add zc notification flush requests"
  selftests/net: temporarily disable io_uring zc test
  io_uring/net: fix overexcessive retries
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux</title>
<updated>2022-09-02T22:24:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-09-02T22:24:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0c95f02269a1ef6c3fae4f46bbdd7a4578d44b8f'/>
<id>0c95f02269a1ef6c3fae4f46bbdd7a4578d44b8f</id>
<content type='text'>
Pull landlock fix from Mickaël Salaün:
 "This fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right when
  multiple rulesets/domains are stacked.

  The expected behaviour was that an additional ruleset can only
  restrict the set of permitted operations, but in this particular case,
  it was potentially possible to re-gain the LANDLOCK_ACCESS_FS_REFER
  right"

* tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull landlock fix from Mickaël Salaün:
 "This fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right when
  multiple rulesets/domains are stacked.

  The expected behaviour was that an additional ruleset can only
  restrict the set of permitted operations, but in this particular case,
  it was potentially possible to re-gain the LANDLOCK_ACCESS_FS_REFER
  right"

* tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER
</pre>
</div>
</content>
</entry>
<entry>
<title>landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER</title>
<updated>2022-09-02T13:29:08+00:00</updated>
<author>
<name>Mickaël Salaün</name>
<email>mic@digikod.net</email>
</author>
<published>2022-08-31T20:38:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=55e55920bbe3ccf516022c51f5527e7d026b8f1d'/>
<id>55e55920bbe3ccf516022c51f5527e7d026b8f1d</id>
<content type='text'>
This change fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right
when multiple rulesets/domains are stacked. The expected behaviour was
that an additional ruleset can only restrict the set of permitted
operations, but in this particular case, it was potentially possible to
re-gain the LANDLOCK_ACCESS_FS_REFER right.

With the introduction of LANDLOCK_ACCESS_FS_REFER, we added the first
globally denied-by-default access right.  Indeed, this lifted an initial
Landlock limitation to rename and link files, which was initially always
denied when the source or the destination were different directories.

This led to an inconsistent backward compatibility behavior which was
only taken into account if no domain layer were using the new
LANDLOCK_ACCESS_FS_REFER right. However, when restricting a thread with
a new ruleset handling LANDLOCK_ACCESS_FS_REFER, all inherited parent
rulesets/layers not explicitly handling LANDLOCK_ACCESS_FS_REFER would
behave as if they were handling this access right and with all their
rules allowing it. This means that renaming and linking files could
became allowed by these parent layers, but all the other required
accesses must also be granted: all layers must allow file removal or
creation, and renaming and linking operations cannot lead to privilege
escalation according to the Landlock policy.  See detailed explanation
in commit b91c3e4ea756 ("landlock: Add support for file reparenting with
LANDLOCK_ACCESS_FS_REFER").

To say it another way, this bug may lift the renaming and linking
limitations of the initial Landlock version, and a same ruleset can
enforce different restrictions depending on previous or next enforced
ruleset (i.e. inconsistent behavior). The LANDLOCK_ACCESS_FS_REFER right
cannot give access to data not already allowed, but this doesn't follow
the contract of the first Landlock ABI. This fix puts back the
limitation for sandboxes that didn't opt-in for this additional right.

For instance, if a first ruleset allows LANDLOCK_ACCESS_FS_MAKE_REG on
/dst and LANDLOCK_ACCESS_FS_REMOVE_FILE on /src, renaming /src/file to
/dst/file is denied. However, without this fix, stacking a new ruleset
which allows LANDLOCK_ACCESS_FS_REFER on / would now permit the
sandboxed thread to rename /src/file to /dst/file .

This change fixes the (absolute) rule access rights, which now always
forbid LANDLOCK_ACCESS_FS_REFER except when it is explicitly allowed
when creating a rule.

Making all domain handle LANDLOCK_ACCESS_FS_REFER was an initial
approach but there is two downsides:
* it makes the code more complex because we still want to check that a
  rule allowing LANDLOCK_ACCESS_FS_REFER is legitimate according to the
  ruleset's handled access rights (i.e. ABI v1 != ABI v2);
* it would not allow to identify if the user created a ruleset
  explicitly handling LANDLOCK_ACCESS_FS_REFER or not, which will be an
  issue to audit Landlock.

Instead, this change adds an ACCESS_INITIALLY_DENIED list of
denied-by-default rights, which (only) contains
LANDLOCK_ACCESS_FS_REFER.  All domains are treated as if they are also
handling this list, but without modifying their fs_access_masks field.

A side effect is that the errno code returned by rename(2) or link(2)
*may* be changed from EXDEV to EACCES according to the enforced
restrictions.  Indeed, we now have the mechanic to identify if an access
is denied because of a required right (e.g. LANDLOCK_ACCESS_FS_MAKE_REG,
LANDLOCK_ACCESS_FS_REMOVE_FILE) or if it is denied because of missing
LANDLOCK_ACCESS_FS_REFER rights.  This may result in different errno
codes than for the initial Landlock version, but this approach is more
consistent and better for rename/link compatibility reasons, and it
wasn't possible before (hence no backport to ABI v1).  The
layout1.rename_file test reflects this change.

Add 4 layout1.refer_denied_by_default* test suites to check that the
behavior of a ruleset not handling LANDLOCK_ACCESS_FS_REFER (ABI v1) is
unchanged even if another layer handles LANDLOCK_ACCESS_FS_REFER (i.e.
ABI v1 precedence).  Make sure rule's absolute access rights are correct
by testing with and without a matching path.  Add test_rename() and
test_exchange() helpers.

Extend layout1.inval tests to check that a denied-by-default access
right is not necessarily part of a domain's handled access rights.

Test coverage for security/landlock is 95.3% of 599 lines according to
gcc/gcov-11.

Fixes: b91c3e4ea756 ("landlock: Add support for file reparenting with LANDLOCK_ACCESS_FS_REFER")
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Reviewed-by: Günther Noack &lt;gnoack3000@gmail.com&gt;
Link: https://lore.kernel.org/r/20220831203840.1370732-1-mic@digikod.net
Cc: stable@vger.kernel.org
[mic: Constify and slightly simplify test helpers]
Signed-off-by: Mickaël Salaün &lt;mic@digikod.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This change fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right
when multiple rulesets/domains are stacked. The expected behaviour was
that an additional ruleset can only restrict the set of permitted
operations, but in this particular case, it was potentially possible to
re-gain the LANDLOCK_ACCESS_FS_REFER right.

With the introduction of LANDLOCK_ACCESS_FS_REFER, we added the first
globally denied-by-default access right.  Indeed, this lifted an initial
Landlock limitation to rename and link files, which was initially always
denied when the source or the destination were different directories.

This led to an inconsistent backward compatibility behavior which was
only taken into account if no domain layer were using the new
LANDLOCK_ACCESS_FS_REFER right. However, when restricting a thread with
a new ruleset handling LANDLOCK_ACCESS_FS_REFER, all inherited parent
rulesets/layers not explicitly handling LANDLOCK_ACCESS_FS_REFER would
behave as if they were handling this access right and with all their
rules allowing it. This means that renaming and linking files could
became allowed by these parent layers, but all the other required
accesses must also be granted: all layers must allow file removal or
creation, and renaming and linking operations cannot lead to privilege
escalation according to the Landlock policy.  See detailed explanation
in commit b91c3e4ea756 ("landlock: Add support for file reparenting with
LANDLOCK_ACCESS_FS_REFER").

To say it another way, this bug may lift the renaming and linking
limitations of the initial Landlock version, and a same ruleset can
enforce different restrictions depending on previous or next enforced
ruleset (i.e. inconsistent behavior). The LANDLOCK_ACCESS_FS_REFER right
cannot give access to data not already allowed, but this doesn't follow
the contract of the first Landlock ABI. This fix puts back the
limitation for sandboxes that didn't opt-in for this additional right.

For instance, if a first ruleset allows LANDLOCK_ACCESS_FS_MAKE_REG on
/dst and LANDLOCK_ACCESS_FS_REMOVE_FILE on /src, renaming /src/file to
/dst/file is denied. However, without this fix, stacking a new ruleset
which allows LANDLOCK_ACCESS_FS_REFER on / would now permit the
sandboxed thread to rename /src/file to /dst/file .

This change fixes the (absolute) rule access rights, which now always
forbid LANDLOCK_ACCESS_FS_REFER except when it is explicitly allowed
when creating a rule.

Making all domain handle LANDLOCK_ACCESS_FS_REFER was an initial
approach but there is two downsides:
* it makes the code more complex because we still want to check that a
  rule allowing LANDLOCK_ACCESS_FS_REFER is legitimate according to the
  ruleset's handled access rights (i.e. ABI v1 != ABI v2);
* it would not allow to identify if the user created a ruleset
  explicitly handling LANDLOCK_ACCESS_FS_REFER or not, which will be an
  issue to audit Landlock.

Instead, this change adds an ACCESS_INITIALLY_DENIED list of
denied-by-default rights, which (only) contains
LANDLOCK_ACCESS_FS_REFER.  All domains are treated as if they are also
handling this list, but without modifying their fs_access_masks field.

A side effect is that the errno code returned by rename(2) or link(2)
*may* be changed from EXDEV to EACCES according to the enforced
restrictions.  Indeed, we now have the mechanic to identify if an access
is denied because of a required right (e.g. LANDLOCK_ACCESS_FS_MAKE_REG,
LANDLOCK_ACCESS_FS_REMOVE_FILE) or if it is denied because of missing
LANDLOCK_ACCESS_FS_REFER rights.  This may result in different errno
codes than for the initial Landlock version, but this approach is more
consistent and better for rename/link compatibility reasons, and it
wasn't possible before (hence no backport to ABI v1).  The
layout1.rename_file test reflects this change.

Add 4 layout1.refer_denied_by_default* test suites to check that the
behavior of a ruleset not handling LANDLOCK_ACCESS_FS_REFER (ABI v1) is
unchanged even if another layer handles LANDLOCK_ACCESS_FS_REFER (i.e.
ABI v1 precedence).  Make sure rule's absolute access rights are correct
by testing with and without a matching path.  Add test_rename() and
test_exchange() helpers.

Extend layout1.inval tests to check that a denied-by-default access
right is not necessarily part of a domain's handled access rights.

Test coverage for security/landlock is 95.3% of 599 lines according to
gcc/gcov-11.

Fixes: b91c3e4ea756 ("landlock: Add support for file reparenting with LANDLOCK_ACCESS_FS_REFER")
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Reviewed-by: Günther Noack &lt;gnoack3000@gmail.com&gt;
Link: https://lore.kernel.org/r/20220831203840.1370732-1-mic@digikod.net
Cc: stable@vger.kernel.org
[mic: Constify and slightly simplify test helpers]
Signed-off-by: Mickaël Salaün &lt;mic@digikod.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kvm-s390-master-6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD</title>
<updated>2022-09-01T23:21:27+00:00</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-09-01T23:21:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=29250ba51bc1cbe8a87e923f76978b87c3247a8c'/>
<id>29250ba51bc1cbe8a87e923f76978b87c3247a8c</id>
<content type='text'>
PCI interpretation compile fixes
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PCI interpretation compile fixes
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/net: return back io_uring zc send tests</title>
<updated>2022-09-01T15:13:33+00:00</updated>
<author>
<name>Pavel Begunkov</name>
<email>asml.silence@gmail.com</email>
</author>
<published>2022-09-01T10:54:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=916d72c10a4ca80ea51f1421e774cb765b53f28f'/>
<id>916d72c10a4ca80ea51f1421e774cb765b53f28f</id>
<content type='text'>
Enable io_uring zerocopy send tests back and fix them up to follow the
new inteface.

Signed-off-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/c8e5018c516093bdad0b6e19f2f9847dea17e4d2.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Enable io_uring zerocopy send tests back and fix them up to follow the
new inteface.

Signed-off-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/c8e5018c516093bdad0b6e19f2f9847dea17e4d2.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/net: temporarily disable io_uring zc test</title>
<updated>2022-09-01T15:13:33+00:00</updated>
<author>
<name>Pavel Begunkov</name>
<email>asml.silence@gmail.com</email>
</author>
<published>2022-09-01T10:54:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=75847100c351c7a49dddd60d1d023bd3e6640682'/>
<id>75847100c351c7a49dddd60d1d023bd3e6640682</id>
<content type='text'>
We're going to change API, to avoid build problems with a couple of
following commits, disable io_uring testing.

Signed-off-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/12b7507223df04fbd12aa05fc0cb544b51d7ed79.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We're going to change API, to avoid build problems with a couple of
following commits, disable io_uring testing.

Signed-off-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/12b7507223df04fbd12aa05fc0cb544b51d7ed79.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: net: sort .gitignore file</title>
<updated>2022-08-31T19:47:57+00:00</updated>
<author>
<name>Axel Rasmussen</name>
<email>axelrasmussen@google.com</email>
</author>
<published>2022-08-29T18:47:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5a3a59981027b53ec0f729ad76a43ce2b64ad968'/>
<id>5a3a59981027b53ec0f729ad76a43ce2b64ad968</id>
<content type='text'>
This is the result of `sort tools/testing/selftests/net/.gitignore`, but
preserving the comment at the top.

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Axel Rasmussen &lt;axelrasmussen@google.com&gt;
Link: https://lore.kernel.org/r/20220829184748.1535580-1-axelrasmussen@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the result of `sort tools/testing/selftests/net/.gitignore`, but
preserving the comment at the top.

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Axel Rasmussen &lt;axelrasmussen@google.com&gt;
Link: https://lore.kernel.org/r/20220829184748.1535580-1-axelrasmussen@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
