<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git, branch v6.6.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Linux 6.6.78</title>
<updated>2025-02-17T08:40:43+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2025-02-17T08:40:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4407146cf3fcfe8883f6123b89f861a11cc4e4df'/>
<id>4407146cf3fcfe8883f6123b89f861a11cc4e4df</id>
<content type='text'>
Link: https://lore.kernel.org/r/20250213142407.354217048@linuxfoundation.org
Tested-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Mark Brown &lt;broonie@kernel.org&gt;
Tested-by: Hardik Garg &lt;hargar@linux.microsoft.com&gt;
Tested-by: Peter Schneider &lt;pschneider1968@googlemail.com&gt;
Tested-by: Ron Economos &lt;re@w6rz.net&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Tested-By: Achill Gilgenast &lt;fossdd@pwned.life&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Link: https://lore.kernel.org/r/20250213142407.354217048@linuxfoundation.org
Tested-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Mark Brown &lt;broonie@kernel.org&gt;
Tested-by: Hardik Garg &lt;hargar@linux.microsoft.com&gt;
Tested-by: Peter Schneider &lt;pschneider1968@googlemail.com&gt;
Tested-by: Ron Economos &lt;re@w6rz.net&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Tested-By: Achill Gilgenast &lt;fossdd@pwned.life&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: Re-split x2APIC ICR into ICR+ICR2 for AMD (x2AVIC)</title>
<updated>2025-02-17T08:40:43+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2024-07-19T23:51:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e8ad068c6ab84e92359686e841451149bbc3d220'/>
<id>e8ad068c6ab84e92359686e841451149bbc3d220</id>
<content type='text'>
commit 73b42dc69be8564d4951a14d00f827929fe5ef79 upstream.

Re-introduce the "split" x2APIC ICR storage that KVM used prior to Intel's
IPI virtualization support, but only for AMD.  While not stated anywhere
in the APM, despite stating the ICR is a single 64-bit register, AMD CPUs
store the 64-bit ICR as two separate 32-bit values in ICR and ICR2.  When
IPI virtualization (IPIv on Intel, all AVIC flavors on AMD) is enabled,
KVM needs to match CPU behavior as some ICR ICR writes will be handled by
the CPU, not by KVM.

Add a kvm_x86_ops knob to control the underlying format used by the CPU to
store the x2APIC ICR, and tune it to AMD vs. Intel regardless of whether
or not x2AVIC is enabled.  If KVM is handling all ICR writes, the storage
format for x2APIC mode doesn't matter, and having the behavior follow AMD
versus Intel will provide better test coverage and ease debugging.

Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky &lt;mlevitsk@redhat.com&gt;
Cc: Suravee Suthikulpanit &lt;suravee.suthikulpanit@amd.com&gt;
Link: https://lore.kernel.org/r/20240719235107.3023592-4-seanjc@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
[JH: fixed conflict with vmx_x86_ops reshuffle due to missing commit 5f18c642ff7e2]
Signed-off-by: James Houghton &lt;jthoughton@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 73b42dc69be8564d4951a14d00f827929fe5ef79 upstream.

Re-introduce the "split" x2APIC ICR storage that KVM used prior to Intel's
IPI virtualization support, but only for AMD.  While not stated anywhere
in the APM, despite stating the ICR is a single 64-bit register, AMD CPUs
store the 64-bit ICR as two separate 32-bit values in ICR and ICR2.  When
IPI virtualization (IPIv on Intel, all AVIC flavors on AMD) is enabled,
KVM needs to match CPU behavior as some ICR ICR writes will be handled by
the CPU, not by KVM.

Add a kvm_x86_ops knob to control the underlying format used by the CPU to
store the x2APIC ICR, and tune it to AMD vs. Intel regardless of whether
or not x2AVIC is enabled.  If KVM is handling all ICR writes, the storage
format for x2APIC mode doesn't matter, and having the behavior follow AMD
versus Intel will provide better test coverage and ease debugging.

Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky &lt;mlevitsk@redhat.com&gt;
Cc: Suravee Suthikulpanit &lt;suravee.suthikulpanit@amd.com&gt;
Link: https://lore.kernel.org/r/20240719235107.3023592-4-seanjc@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
[JH: fixed conflict with vmx_x86_ops reshuffle due to missing commit 5f18c642ff7e2]
Signed-off-by: James Houghton &lt;jthoughton@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: Make x2APIC ID 100% readonly</title>
<updated>2025-02-17T08:40:43+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2024-08-02T20:29:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4fc0f9eadda8ee5ca4eabdcc87d9f59fc25001cd'/>
<id>4fc0f9eadda8ee5ca4eabdcc87d9f59fc25001cd</id>
<content type='text'>
commit 4b7c3f6d04bd53f2e5b228b6821fb8f5d1ba3071 upstream.

Ignore the userspace provided x2APIC ID when fixing up APIC state for
KVM_SET_LAPIC, i.e. make the x2APIC fully readonly in KVM.  Commit
a92e2543d6a8 ("KVM: x86: use hardware-compatible format for APIC ID
register"), which added the fixup, didn't intend to allow userspace to
modify the x2APIC ID.  In fact, that commit is when KVM first started
treating the x2APIC ID as readonly, apparently to fix some race:

 static inline u32 kvm_apic_id(struct kvm_lapic *apic)
 {
-       return (kvm_lapic_get_reg(apic, APIC_ID) &gt;&gt; 24) &amp; 0xff;
+       /* To avoid a race between apic_base and following APIC_ID update when
+        * switching to x2apic_mode, the x2apic mode returns initial x2apic id.
+        */
+       if (apic_x2apic_mode(apic))
+               return apic-&gt;vcpu-&gt;vcpu_id;
+
+       return kvm_lapic_get_reg(apic, APIC_ID) &gt;&gt; 24;
 }

Furthermore, KVM doesn't support delivering interrupts to vCPUs with a
modified x2APIC ID, but KVM *does* return the modified value on a guest
RDMSR and for KVM_GET_LAPIC.  I.e. no remotely sane setup can actually
work with a modified x2APIC ID.

Making the x2APIC ID fully readonly fixes a WARN in KVM's optimized map
calculation, which expects the LDR to align with the x2APIC ID.

  WARNING: CPU: 2 PID: 958 at arch/x86/kvm/lapic.c:331 kvm_recalculate_apic_map+0x609/0xa00 [kvm]
  CPU: 2 PID: 958 Comm: recalc_apic_map Not tainted 6.4.0-rc3-vanilla+ #35
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.2-1-1 04/01/2014
  RIP: 0010:kvm_recalculate_apic_map+0x609/0xa00 [kvm]
  Call Trace:
   &lt;TASK&gt;
   kvm_apic_set_state+0x1cf/0x5b0 [kvm]
   kvm_arch_vcpu_ioctl+0x1806/0x2100 [kvm]
   kvm_vcpu_ioctl+0x663/0x8a0 [kvm]
   __x64_sys_ioctl+0xb8/0xf0
   do_syscall_64+0x56/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0
  RIP: 0033:0x7fade8b9dd6f

Unfortunately, the WARN can still trigger for other CPUs than the current
one by racing against KVM_SET_LAPIC, so remove it completely.

Reported-by: Michal Luczaj &lt;mhal@rbox.co&gt;
Closes: https://lore.kernel.org/all/814baa0c-1eaa-4503-129f-059917365e80@rbox.co
Reported-by: Haoyu Wu &lt;haoyuwu254@gmail.com&gt;
Closes: https://lore.kernel.org/all/20240126161633.62529-1-haoyuwu254@gmail.com
Reported-by: syzbot+545f1326f405db4e1c3e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000c2a6b9061cbca3c3@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Message-ID: &lt;20240802202941.344889-2-seanjc@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: James Houghton &lt;jthoughton@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4b7c3f6d04bd53f2e5b228b6821fb8f5d1ba3071 upstream.

Ignore the userspace provided x2APIC ID when fixing up APIC state for
KVM_SET_LAPIC, i.e. make the x2APIC fully readonly in KVM.  Commit
a92e2543d6a8 ("KVM: x86: use hardware-compatible format for APIC ID
register"), which added the fixup, didn't intend to allow userspace to
modify the x2APIC ID.  In fact, that commit is when KVM first started
treating the x2APIC ID as readonly, apparently to fix some race:

 static inline u32 kvm_apic_id(struct kvm_lapic *apic)
 {
-       return (kvm_lapic_get_reg(apic, APIC_ID) &gt;&gt; 24) &amp; 0xff;
+       /* To avoid a race between apic_base and following APIC_ID update when
+        * switching to x2apic_mode, the x2apic mode returns initial x2apic id.
+        */
+       if (apic_x2apic_mode(apic))
+               return apic-&gt;vcpu-&gt;vcpu_id;
+
+       return kvm_lapic_get_reg(apic, APIC_ID) &gt;&gt; 24;
 }

Furthermore, KVM doesn't support delivering interrupts to vCPUs with a
modified x2APIC ID, but KVM *does* return the modified value on a guest
RDMSR and for KVM_GET_LAPIC.  I.e. no remotely sane setup can actually
work with a modified x2APIC ID.

Making the x2APIC ID fully readonly fixes a WARN in KVM's optimized map
calculation, which expects the LDR to align with the x2APIC ID.

  WARNING: CPU: 2 PID: 958 at arch/x86/kvm/lapic.c:331 kvm_recalculate_apic_map+0x609/0xa00 [kvm]
  CPU: 2 PID: 958 Comm: recalc_apic_map Not tainted 6.4.0-rc3-vanilla+ #35
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.2-1-1 04/01/2014
  RIP: 0010:kvm_recalculate_apic_map+0x609/0xa00 [kvm]
  Call Trace:
   &lt;TASK&gt;
   kvm_apic_set_state+0x1cf/0x5b0 [kvm]
   kvm_arch_vcpu_ioctl+0x1806/0x2100 [kvm]
   kvm_vcpu_ioctl+0x663/0x8a0 [kvm]
   __x64_sys_ioctl+0xb8/0xf0
   do_syscall_64+0x56/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0
  RIP: 0033:0x7fade8b9dd6f

Unfortunately, the WARN can still trigger for other CPUs than the current
one by racing against KVM_SET_LAPIC, so remove it completely.

Reported-by: Michal Luczaj &lt;mhal@rbox.co&gt;
Closes: https://lore.kernel.org/all/814baa0c-1eaa-4503-129f-059917365e80@rbox.co
Reported-by: Haoyu Wu &lt;haoyuwu254@gmail.com&gt;
Closes: https://lore.kernel.org/all/20240126161633.62529-1-haoyuwu254@gmail.com
Reported-by: syzbot+545f1326f405db4e1c3e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000c2a6b9061cbca3c3@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Message-ID: &lt;20240802202941.344889-2-seanjc@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: James Houghton &lt;jthoughton@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: xilinx_uartps: split sysrq handling</title>
<updated>2025-02-17T08:40:43+00:00</updated>
<author>
<name>Sean Anderson</name>
<email>sean.anderson@linux.dev</email>
</author>
<published>2025-01-10T21:38:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c'/>
<id>8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c</id>
<content type='text'>
commit b06f388994500297bb91be60ffaf6825ecfd2afe upstream.

lockdep detects the following circular locking dependency:

CPU 0                      CPU 1
========================== ============================
cdns_uart_isr()            printk()
  uart_port_lock(port)       console_lock()
			     cdns_uart_console_write()
                               if (!port-&gt;sysrq)
                                 uart_port_lock(port)
  uart_handle_break()
    port-&gt;sysrq = ...
  uart_handle_sysrq_char()
    printk()
      console_lock()

The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port-&gt;sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port-&gt;sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock.

Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.

Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling")
Signed-off-by: Sean Anderson &lt;sean.anderson@linux.dev&gt;
Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers
Acked-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev
Signed-off-by: Sean Anderson &lt;sean.anderson@linux.dev&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b06f388994500297bb91be60ffaf6825ecfd2afe upstream.

lockdep detects the following circular locking dependency:

CPU 0                      CPU 1
========================== ============================
cdns_uart_isr()            printk()
  uart_port_lock(port)       console_lock()
			     cdns_uart_console_write()
                               if (!port-&gt;sysrq)
                                 uart_port_lock(port)
  uart_handle_break()
    port-&gt;sysrq = ...
  uart_handle_sysrq_char()
    printk()
      console_lock()

The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port-&gt;sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port-&gt;sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock.

Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.

Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling")
Signed-off-by: Sean Anderson &lt;sean.anderson@linux.dev&gt;
Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers
Acked-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev
Signed-off-by: Sean Anderson &lt;sean.anderson@linux.dev&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/mm/ident_map: Use gbpages only where full GB page should be mapped.</title>
<updated>2025-02-17T08:40:43+00:00</updated>
<author>
<name>Steve Wahl</name>
<email>steve.wahl@hpe.com</email>
</author>
<published>2024-07-17T21:31:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d113f9723f2bfd9c6feeb899b8ddbee6b8a6e01f'/>
<id>d113f9723f2bfd9c6feeb899b8ddbee6b8a6e01f</id>
<content type='text'>
commit cc31744a294584a36bf764a0ffa3255a8e69f036 upstream.

When ident_pud_init() uses only GB pages to create identity maps, large
ranges of addresses not actually requested can be included in the resulting
table; a 4K request will map a full GB.  This can include a lot of extra
address space past that requested, including areas marked reserved by the
BIOS.  That allows processor speculation into reserved regions, that on UV
systems can cause system halts.

Only use GB pages when map creation requests include the full GB page of
space.  Fall back to using smaller 2M pages when only portions of a GB page
are included in the request.

No attempt is made to coalesce mapping requests. If a request requires a
map entry at the 2M (pmd) level, subsequent mapping requests within the
same 1G region will also be at the pmd level, even if adjacent or
overlapping such requests could have been combined to map a full GB page.
Existing usage starts with larger regions and then adds smaller regions, so
this should not have any great consequence.

Signed-off-by: Steve Wahl &lt;steve.wahl@hpe.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Pavin Joseph &lt;me@pavinjoseph.com&gt;
Tested-by: Sarah Brofeldt &lt;srhb@dbc.dk&gt;
Tested-by: Eric Hagberg &lt;ehagberg@gmail.com&gt;
Link: https://lore.kernel.org/all/20240717213121.3064030-3-steve.wahl@hpe.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit cc31744a294584a36bf764a0ffa3255a8e69f036 upstream.

When ident_pud_init() uses only GB pages to create identity maps, large
ranges of addresses not actually requested can be included in the resulting
table; a 4K request will map a full GB.  This can include a lot of extra
address space past that requested, including areas marked reserved by the
BIOS.  That allows processor speculation into reserved regions, that on UV
systems can cause system halts.

Only use GB pages when map creation requests include the full GB page of
space.  Fall back to using smaller 2M pages when only portions of a GB page
are included in the request.

No attempt is made to coalesce mapping requests. If a request requires a
map entry at the 2M (pmd) level, subsequent mapping requests within the
same 1G region will also be at the pmd level, even if adjacent or
overlapping such requests could have been combined to map a full GB page.
Existing usage starts with larger regions and then adds smaller regions, so
this should not have any great consequence.

Signed-off-by: Steve Wahl &lt;steve.wahl@hpe.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Pavin Joseph &lt;me@pavinjoseph.com&gt;
Tested-by: Sarah Brofeldt &lt;srhb@dbc.dk&gt;
Tested-by: Eric Hagberg &lt;ehagberg@gmail.com&gt;
Link: https://lore.kernel.org/all/20240717213121.3064030-3-steve.wahl@hpe.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: mptcp: join: fix AF_INET6 variable</title>
<updated>2025-02-17T08:40:42+00:00</updated>
<author>
<name>Matthieu Baerts (NGI0)</name>
<email>matttbe@kernel.org</email>
</author>
<published>2025-02-09T17:41:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=690c7fa03ebb167916b280a02f4bce3784a78580'/>
<id>690c7fa03ebb167916b280a02f4bce3784a78580</id>
<content type='text'>
The Fixes commit is a backport renaming a variable, from AF_INET6 to
MPTCP_LIB_AF_INET6.

The commit has been applied without conflicts, except that it missed one
extra variable that was in v6.6, but not in the version linked to the
Fixes commit.

This variable has then been renamed too to avoid these errors:

  LISTENER_CREATED 10.0.2.1:10100     ./mptcp_join.sh: line 2944: [: 2: unary operator expected
  LISTENER_CLOSED  10.0.2.1:10100     ./mptcp_join.sh: line 2944: [: 2: unary operator expected

Fixes: a17d1419126b ("selftests: mptcp: declare event macros in mptcp_lib")
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The Fixes commit is a backport renaming a variable, from AF_INET6 to
MPTCP_LIB_AF_INET6.

The commit has been applied without conflicts, except that it missed one
extra variable that was in v6.6, but not in the version linked to the
Fixes commit.

This variable has then been renamed too to avoid these errors:

  LISTENER_CREATED 10.0.2.1:10100     ./mptcp_join.sh: line 2944: [: 2: unary operator expected
  LISTENER_CLOSED  10.0.2.1:10100     ./mptcp_join.sh: line 2944: [: 2: unary operator expected

Fixes: a17d1419126b ("selftests: mptcp: declare event macros in mptcp_lib")
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mptcp: prevent excessive coalescing on receive</title>
<updated>2025-02-17T08:40:42+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2025-02-09T17:41:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a772014594644de89f309a65c1a4308ff1fde6f4'/>
<id>a772014594644de89f309a65c1a4308ff1fde6f4</id>
<content type='text'>
commit 56b824eb49d6258aa0bad09a406ceac3f643cdae upstream.

Currently the skb size after coalescing is only limited by the skb
layout (the skb must not carry frag_list). A single coalesced skb
covering several MSS can potentially fill completely the receive
buffer. In such a case, the snd win will zero until the receive buffer
will be empty again, affecting tput badly.

Fixes: 8268ed4c9d19 ("mptcp: introduce and use mptcp_try_coalesce()")
Cc: stable@vger.kernel.org # please delay 2 weeks after 6.13-final release
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-3-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 56b824eb49d6258aa0bad09a406ceac3f643cdae upstream.

Currently the skb size after coalescing is only limited by the skb
layout (the skb must not carry frag_list). A single coalesced skb
covering several MSS can potentially fill completely the receive
buffer. In such a case, the snd win will zero until the receive buffer
will be empty again, affecting tput badly.

Fixes: 8268ed4c9d19 ("mptcp: introduce and use mptcp_try_coalesce()")
Cc: stable@vger.kernel.org # please delay 2 weeks after 6.13-final release
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-3-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mptcp: pm: only set fullmesh for subflow endp</title>
<updated>2025-02-17T08:40:42+00:00</updated>
<author>
<name>Matthieu Baerts (NGI0)</name>
<email>matttbe@kernel.org</email>
</author>
<published>2025-02-09T17:41:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de3b8d41d2547452c4cafb146d003fa4689fbaf2'/>
<id>de3b8d41d2547452c4cafb146d003fa4689fbaf2</id>
<content type='text'>
commit 1bb0d1348546ad059f55c93def34e67cb2a034a6 upstream.

With the in-kernel path-manager, it is possible to change the 'fullmesh'
flag. The code in mptcp_pm_nl_fullmesh() expects to change it only on
'subflow' endpoints, to recreate more or less subflows using the linked
address.

Unfortunately, the set_flags() hook was a bit more permissive, and
allowed 'implicit' endpoints to get the 'fullmesh' flag while it is not
allowed before.

That's what syzbot found, triggering the following warning:

  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 __mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
  Modules linked in:
  CPU: 0 UID: 0 PID: 6499 Comm: syz.1.413 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0
  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
  RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
  RIP: 0010:mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
  RIP: 0010:mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
  Code: 01 00 00 49 89 c5 e8 fb 45 e8 f5 e9 b8 fc ff ff e8 f1 45 e8 f5 4c 89 f7 be 03 00 00 00 e8 44 1d 0b f9 eb a0 e8 dd 45 e8 f5 90 &lt;0f&gt; 0b 90 e9 17 ff ff ff 89 d9 80 e1 07 38 c1 0f 8c c9 fc ff ff 48
  RSP: 0018:ffffc9000d307240 EFLAGS: 00010293
  RAX: ffffffff8bb72e03 RBX: 0000000000000000 RCX: ffff88807da88000
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffffc9000d307430 R08: ffffffff8bb72cf0 R09: 1ffff1100b842a5e
  R10: dffffc0000000000 R11: ffffed100b842a5f R12: ffff88801e2e5ac0
  R13: ffff88805c214800 R14: ffff88805c2152e8 R15: 1ffff1100b842a5d
  FS:  00005555619f6500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020002840 CR3: 00000000247e6000 CR4: 00000000003526f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   &lt;TASK&gt;
   genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
   genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
   netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542
   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
   netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
   netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
   netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
   sock_sendmsg_nosec net/socket.c:711 [inline]
   __sock_sendmsg+0x221/0x270 net/socket.c:726
   ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
   ___sys_sendmsg net/socket.c:2637 [inline]
   __sys_sendmsg+0x269/0x350 net/socket.c:2669
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f5fe8785d29
  Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007fff571f5558 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007f5fe8975fa0 RCX: 00007f5fe8785d29
  RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000007
  RBP: 00007f5fe8801b08 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007f5fe8975fa0 R14: 00007f5fe8975fa0 R15: 00000000000011f4
   &lt;/TASK&gt;

Here, syzbot managed to set the 'fullmesh' flag on an 'implicit' and
used -- according to 'id_avail_bitmap' -- endpoint, causing the PM to
try decrement the local_addr_used counter which is only incremented for
the 'subflow' endpoint.

Note that 'no type' endpoints -- not 'subflow', 'signal', 'implicit' --
are fine, because their ID will not be marked as used in the 'id_avail'
bitmap, and setting 'fullmesh' can help forcing the creation of subflow
when receiving an ADD_ADDR.

Fixes: 73c762c1f07d ("mptcp: set fullmesh flag in pm_netlink")
Cc: stable@vger.kernel.org
Reported-by: syzbot+cd16e79c1e45f3fe0377@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/6786ac51.050a0220.216c54.00a6.GAE@google.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/540
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20250123-net-mptcp-syzbot-issues-v1-2-af73258a726f@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
[ Conflicts in pm_netlink.c, because the code has been moved around in
  commit 6a42477fe449 ("mptcp: update set_flags interfaces"), but the
  same fix can still be applied at the original place. ]
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1bb0d1348546ad059f55c93def34e67cb2a034a6 upstream.

With the in-kernel path-manager, it is possible to change the 'fullmesh'
flag. The code in mptcp_pm_nl_fullmesh() expects to change it only on
'subflow' endpoints, to recreate more or less subflows using the linked
address.

Unfortunately, the set_flags() hook was a bit more permissive, and
allowed 'implicit' endpoints to get the 'fullmesh' flag while it is not
allowed before.

That's what syzbot found, triggering the following warning:

  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 __mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
  WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
  Modules linked in:
  CPU: 0 UID: 0 PID: 6499 Comm: syz.1.413 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0
  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
  RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
  RIP: 0010:mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
  RIP: 0010:mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
  Code: 01 00 00 49 89 c5 e8 fb 45 e8 f5 e9 b8 fc ff ff e8 f1 45 e8 f5 4c 89 f7 be 03 00 00 00 e8 44 1d 0b f9 eb a0 e8 dd 45 e8 f5 90 &lt;0f&gt; 0b 90 e9 17 ff ff ff 89 d9 80 e1 07 38 c1 0f 8c c9 fc ff ff 48
  RSP: 0018:ffffc9000d307240 EFLAGS: 00010293
  RAX: ffffffff8bb72e03 RBX: 0000000000000000 RCX: ffff88807da88000
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffffc9000d307430 R08: ffffffff8bb72cf0 R09: 1ffff1100b842a5e
  R10: dffffc0000000000 R11: ffffed100b842a5f R12: ffff88801e2e5ac0
  R13: ffff88805c214800 R14: ffff88805c2152e8 R15: 1ffff1100b842a5d
  FS:  00005555619f6500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020002840 CR3: 00000000247e6000 CR4: 00000000003526f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   &lt;TASK&gt;
   genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
   genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
   netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542
   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
   netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
   netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
   netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
   sock_sendmsg_nosec net/socket.c:711 [inline]
   __sock_sendmsg+0x221/0x270 net/socket.c:726
   ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
   ___sys_sendmsg net/socket.c:2637 [inline]
   __sys_sendmsg+0x269/0x350 net/socket.c:2669
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f5fe8785d29
  Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007fff571f5558 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007f5fe8975fa0 RCX: 00007f5fe8785d29
  RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000007
  RBP: 00007f5fe8801b08 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007f5fe8975fa0 R14: 00007f5fe8975fa0 R15: 00000000000011f4
   &lt;/TASK&gt;

Here, syzbot managed to set the 'fullmesh' flag on an 'implicit' and
used -- according to 'id_avail_bitmap' -- endpoint, causing the PM to
try decrement the local_addr_used counter which is only incremented for
the 'subflow' endpoint.

Note that 'no type' endpoints -- not 'subflow', 'signal', 'implicit' --
are fine, because their ID will not be marked as used in the 'id_avail'
bitmap, and setting 'fullmesh' can help forcing the creation of subflow
when receiving an ADD_ADDR.

Fixes: 73c762c1f07d ("mptcp: set fullmesh flag in pm_netlink")
Cc: stable@vger.kernel.org
Reported-by: syzbot+cd16e79c1e45f3fe0377@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/6786ac51.050a0220.216c54.00a6.GAE@google.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/540
Reviewed-by: Mat Martineau &lt;martineau@kernel.org&gt;
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Link: https://patch.msgid.link/20250123-net-mptcp-syzbot-issues-v1-2-af73258a726f@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
[ Conflicts in pm_netlink.c, because the code has been moved around in
  commit 6a42477fe449 ("mptcp: update set_flags interfaces"), but the
  same fix can still be applied at the original place. ]
Signed-off-by: Matthieu Baerts (NGI0) &lt;matttbe@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cachefiles: Fix NULL pointer dereference in object-&gt;file</title>
<updated>2025-02-17T08:40:42+00:00</updated>
<author>
<name>Zizhi Wo</name>
<email>wozizhi@huawei.com</email>
</author>
<published>2024-11-07T11:06:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=785408bbafcfa24c9fc5b251f03fd0780ce182bd'/>
<id>785408bbafcfa24c9fc5b251f03fd0780ce182bd</id>
<content type='text'>
commit 31ad74b20227ce6b40910ff78b1c604e42975cf1 upstream.

At present, the object-&gt;file has the NULL pointer dereference problem in
ondemand-mode. The root cause is that the allocated fd and object-&gt;file
lifetime are inconsistent, and the user-space invocation to anon_fd uses
object-&gt;file. Following is the process that triggers the issue:

	  [write fd]				[umount]
cachefiles_ondemand_fd_write_iter
				       fscache_cookie_state_machine
					 cachefiles_withdraw_cookie
  if (!file) return -ENOBUFS
					   cachefiles_clean_up_object
					     cachefiles_unmark_inode_in_use
					     fput(object-&gt;file)
					     object-&gt;file = NULL
  // file NULL pointer dereference!
  __cachefiles_write(..., file, ...)

Fix this issue by add an additional reference count to the object-&gt;file
before write/llseek, and decrement after it finished.

Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie")
Signed-off-by: Zizhi Wo &lt;wozizhi@huawei.com&gt;
Link: https://lore.kernel.org/r/20241107110649.3980193-5-wozizhi@huawei.com
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Bin Lan &lt;lanbincn@qq.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 31ad74b20227ce6b40910ff78b1c604e42975cf1 upstream.

At present, the object-&gt;file has the NULL pointer dereference problem in
ondemand-mode. The root cause is that the allocated fd and object-&gt;file
lifetime are inconsistent, and the user-space invocation to anon_fd uses
object-&gt;file. Following is the process that triggers the issue:

	  [write fd]				[umount]
cachefiles_ondemand_fd_write_iter
				       fscache_cookie_state_machine
					 cachefiles_withdraw_cookie
  if (!file) return -ENOBUFS
					   cachefiles_clean_up_object
					     cachefiles_unmark_inode_in_use
					     fput(object-&gt;file)
					     object-&gt;file = NULL
  // file NULL pointer dereference!
  __cachefiles_write(..., file, ...)

Fix this issue by add an additional reference count to the object-&gt;file
before write/llseek, and decrement after it finished.

Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie")
Signed-off-by: Zizhi Wo &lt;wozizhi@huawei.com&gt;
Link: https://lore.kernel.org/r/20241107110649.3980193-5-wozizhi@huawei.com
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Bin Lan &lt;lanbincn@qq.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: avoid monopolizing a core when activating a swap file</title>
<updated>2025-02-17T08:40:42+00:00</updated>
<author>
<name>Filipe Manana</name>
<email>fdmanana@suse.com</email>
</author>
<published>2025-02-06T16:21:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=893b28374aba25f78a34befb184624eebb468ab6'/>
<id>893b28374aba25f78a34befb184624eebb468ab6</id>
<content type='text'>
commit 2c8507c63f5498d4ee4af404a8e44ceae4345056 upstream.

This commit re-attempts the backport of the change to the linux-6.6.y
branch. Commit 6e1a82259307 ("btrfs: avoid monopolizing a core when
activating a swap file") on this branch was reverted.

During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Koichiro Den &lt;koichiro.den@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2c8507c63f5498d4ee4af404a8e44ceae4345056 upstream.

This commit re-attempts the backport of the change to the linux-6.6.y
branch. Commit 6e1a82259307 ("btrfs: avoid monopolizing a core when
activating a swap file") on this branch was reverted.

During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Koichiro Den &lt;koichiro.den@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
