<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel, branch v6.9.9</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>swap: yield device immediately</title>
<updated>2024-07-11T10:51:22+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2024-05-21T19:00:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d143321f8392f9598659ef2ac2dee592a03aae65'/>
<id>d143321f8392f9598659ef2ac2dee592a03aae65</id>
<content type='text'>
[ Upstream commit 712182b67e831912f90259102ae334089e7bccd1 ]

Otherwise we can cause spurious EBUSY issues when trying to mount the
rootfs later on.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218845
Reported-by: Petri Kaukasoina &lt;petri.kaukasoina@tuni.fi&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 712182b67e831912f90259102ae334089e7bccd1 ]

Otherwise we can cause spurious EBUSY issues when trying to mount the
rootfs later on.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218845
Reported-by: Petri Kaukasoina &lt;petri.kaukasoina@tuni.fi&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-mapping: benchmark: avoid needless copy_to_user if benchmark fails</title>
<updated>2024-07-11T10:51:21+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2024-05-04T11:47:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8108b176ea37fa86c1c2b25335eec8b9177a212a'/>
<id>8108b176ea37fa86c1c2b25335eec8b9177a212a</id>
<content type='text'>
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ]

If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.

Suggested-by: Barry Song &lt;21cnbao@gmail.com&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ]

If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.

Suggested-by: Barry Song &lt;21cnbao@gmail.com&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: optimize the redundant loop of mm_update_owner_next()</title>
<updated>2024-07-11T10:51:15+00:00</updated>
<author>
<name>Jinliang Zheng</name>
<email>alexjlzheng@tencent.com</email>
</author>
<published>2024-06-20T12:21:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8aefb73ee13eafe463ba7934d1d44a6c5d4fda73'/>
<id>8aefb73ee13eafe463ba7934d1d44a6c5d4fda73</id>
<content type='text'>
commit cf3f9a593dab87a032d2b6a6fb205e7f3de4f0a1 upstream.

When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.

If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.

Recognize this situation in advance and exit early.

Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng &lt;alexjlzheng@tencent.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Tycho Andersen &lt;tandersen@netflix.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.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 cf3f9a593dab87a032d2b6a6fb205e7f3de4f0a1 upstream.

When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.

If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.

Recognize this situation in advance and exit early.

Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng &lt;alexjlzheng@tencent.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Tycho Andersen &lt;tandersen@netflix.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vhost_task: Handle SIGKILL by flushing work and exiting</title>
<updated>2024-07-11T10:51:07+00:00</updated>
<author>
<name>Mike Christie</name>
<email>michael.christie@oracle.com</email>
</author>
<published>2024-03-16T00:47:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dec987fe2df670827eb53b97c9552ed8dfc63ad4'/>
<id>dec987fe2df670827eb53b97c9552ed8dfc63ad4</id>
<content type='text'>
[ Upstream commit db5247d9bf5c6ade9fd70b4e4897441e0269b233 ]

Instead of lingering until the device is closed, this has us handle
SIGKILL by:

1. marking the worker as killed so we no longer try to use it with
   new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.

Suggested-by: Edward Adam Davis &lt;eadavis@qq.com&gt;
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: &lt;tencent_546DA49414E876EEBECF2C78D26D242EE50A@qq.com&gt;
Signed-off-by: Mike Christie &lt;michael.christie@oracle.com&gt;
Message-Id: &lt;20240316004707.45557-9-michael.christie@oracle.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit db5247d9bf5c6ade9fd70b4e4897441e0269b233 ]

Instead of lingering until the device is closed, this has us handle
SIGKILL by:

1. marking the worker as killed so we no longer try to use it with
   new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.

Suggested-by: Edward Adam Davis &lt;eadavis@qq.com&gt;
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: &lt;tencent_546DA49414E876EEBECF2C78D26D242EE50A@qq.com&gt;
Signed-off-by: Mike Christie &lt;michael.christie@oracle.com&gt;
Message-Id: &lt;20240316004707.45557-9-michael.christie@oracle.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/mutex: Introduce devm_mutex_init()</title>
<updated>2024-07-11T10:50:55+00:00</updated>
<author>
<name>George Stark</name>
<email>gnstark@salutedevices.com</email>
</author>
<published>2024-04-11T16:10:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f6828e413faa37e2b1366415c97d2315bbbe31d0'/>
<id>f6828e413faa37e2b1366415c97d2315bbbe31d0</id>
<content type='text'>
[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ]

Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init().

Suggested-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: George Stark &lt;gnstark@salutedevices.com&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Reviewed-by: Marek Behún &lt;kabel@kernel.org&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com
Signed-off-by: Lee Jones &lt;lee@kernel.org&gt;
Stable-dep-of: efc347b9efee ("leds: mlxreg: Use devm_mutex_init() for mutex initialization")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ]

Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init().

Suggested-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: George Stark &lt;gnstark@salutedevices.com&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Reviewed-by: Marek Behún &lt;kabel@kernel.org&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com
Signed-off-by: Lee Jones &lt;lee@kernel.org&gt;
Stable-dep-of: efc347b9efee ("leds: mlxreg: Use devm_mutex_init() for mutex initialization")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>syscalls: fix compat_sys_io_pgetevents_time64 usage</title>
<updated>2024-07-05T07:38:16+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2024-06-20T12:16:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7f9155572a58956cec1918fde5d011094c9beb72'/>
<id>7f9155572a58956cec1918fde5d011094c9beb72</id>
<content type='text'>
commit d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream.

Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.

This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.

Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.

Cc: stable@vger.kernel.org
Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens &lt;hca@linux.ibm.com&gt; # s390
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&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 d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream.

Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.

This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.

Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.

Cc: stable@vger.kernel.org
Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens &lt;hca@linux.ibm.com&gt; # s390
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpu/hotplug: Fix dynstate assignment in __cpuhp_setup_state_cpuslocked()</title>
<updated>2024-07-05T07:38:12+00:00</updated>
<author>
<name>Yuntao Wang</name>
<email>ytcoode@gmail.com</email>
</author>
<published>2024-05-15T13:45:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d732f909358ebf4f1e06834e27da10949d29c47'/>
<id>3d732f909358ebf4f1e06834e27da10949d29c47</id>
<content type='text'>
commit 932d8476399f622aa0767a4a0a9e78e5341dc0e1 upstream.

Commit 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare
stage") added a dynamic range for the prepare states, but did not handle
the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().

This causes the corresponding startup callback not to be invoked when
calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN
parameter, even though it should be.

Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or
another, have not triggered this bug.

Fixes: 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage")
Signed-off-by: Yuntao Wang &lt;ytcoode@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.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 932d8476399f622aa0767a4a0a9e78e5341dc0e1 upstream.

Commit 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare
stage") added a dynamic range for the prepare states, but did not handle
the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().

This causes the corresponding startup callback not to be invoked when
calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN
parameter, even though it should be.

Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or
another, have not triggered this bug.

Fixes: 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage")
Signed-off-by: Yuntao Wang &lt;ytcoode@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpu: Fix broken cmdline "nosmp" and "maxcpus=0"</title>
<updated>2024-07-05T07:38:12+00:00</updated>
<author>
<name>Huacai Chen</name>
<email>chenhuacai@loongson.cn</email>
</author>
<published>2024-06-18T08:13:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a4787a05a47431feff64d7f7f46c55c48814fa5c'/>
<id>a4787a05a47431feff64d7f7f46c55c48814fa5c</id>
<content type='text'>
commit 6ef8eb5125722c241fd60d7b0c872d5c2e5dd4ca upstream.

After the rework of "Parallel CPU bringup", the cmdline "nosmp" and
"maxcpus=0" parameters are not working anymore. These parameters set
setup_max_cpus to zero and that's handed to bringup_nonboot_cpus().

The code there does a decrement before checking for zero, which brings it
into the negative space and brings up all CPUs.

Add a zero check at the beginning of the function to prevent this.

[ tglx: Massaged change log ]

Fixes: 18415f33e2ac4ab382 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Fixes: 06c6796e0304234da6 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()")
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
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 6ef8eb5125722c241fd60d7b0c872d5c2e5dd4ca upstream.

After the rework of "Parallel CPU bringup", the cmdline "nosmp" and
"maxcpus=0" parameters are not working anymore. These parameters set
setup_max_cpus to zero and that's handed to bringup_nonboot_cpus().

The code there does a decrement before checking for zero, which brings it
into the negative space and brings up all CPUs.

Add a zero check at the beginning of the function to prevent this.

[ tglx: Massaged change log ]

Fixes: 18415f33e2ac4ab382 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Fixes: 06c6796e0304234da6 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()")
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode</title>
<updated>2024-07-05T07:37:58+00:00</updated>
<author>
<name>Martin KaFai Lau</name>
<email>martin.lau@kernel.org</email>
</author>
<published>2024-03-28T18:58:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3189983c26108cf0990e5c46856dc9feb9470d12'/>
<id>3189983c26108cf0990e5c46856dc9feb9470d12</id>
<content type='text'>
[ Upstream commit e8742081db7d01f980c6161ae1e8a1dbc1e30979 ]

syzbot reported uninit memory usages during map_{lookup,delete}_elem.

==========
BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
__dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]
bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38
___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
__bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237
==========

The reproducer should be in the interpreter mode.

The C reproducer is trying to run the following bpf prog:

    0: (18) r0 = 0x0
    2: (18) r1 = map[id:49]
    4: (b7) r8 = 16777216
    5: (7b) *(u64 *)(r10 -8) = r8
    6: (bf) r2 = r10
    7: (07) r2 += -229
            ^^^^^^^^^^

    8: (b7) r3 = 8
    9: (b7) r4 = 0
   10: (85) call dev_map_lookup_elem#1543472
   11: (95) exit

It is due to the "void *key" (r2) passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.

This should address different syzbot reports on the uninit "void *key"
argument during map_{lookup,delete}_elem.

Reported-by: syzbot+603bcd9b0bf1d94dbb9b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000f9ce6d061494e694@google.com/
Reported-by: syzbot+eb02dc7f03dce0ef39f3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000a5c69c06147c2238@google.com/
Reported-by: syzbot+b4e65ca24fd4d0c734c3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000ac56fb06143b6cfa@google.com/
Reported-by: syzbot+d2b113dc9fea5e1d2848@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000000d69b206142d1ff7@google.com/
Reported-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000006f876b061478e878@google.com/
Tested-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Suggested-by: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Suggested-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://lore.kernel.org/r/20240328185801.1843078-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e8742081db7d01f980c6161ae1e8a1dbc1e30979 ]

syzbot reported uninit memory usages during map_{lookup,delete}_elem.

==========
BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
__dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]
bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38
___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
__bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237
==========

The reproducer should be in the interpreter mode.

The C reproducer is trying to run the following bpf prog:

    0: (18) r0 = 0x0
    2: (18) r1 = map[id:49]
    4: (b7) r8 = 16777216
    5: (7b) *(u64 *)(r10 -8) = r8
    6: (bf) r2 = r10
    7: (07) r2 += -229
            ^^^^^^^^^^

    8: (b7) r3 = 8
    9: (b7) r4 = 0
   10: (85) call dev_map_lookup_elem#1543472
   11: (95) exit

It is due to the "void *key" (r2) passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.

This should address different syzbot reports on the uninit "void *key"
argument during map_{lookup,delete}_elem.

Reported-by: syzbot+603bcd9b0bf1d94dbb9b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000f9ce6d061494e694@google.com/
Reported-by: syzbot+eb02dc7f03dce0ef39f3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000a5c69c06147c2238@google.com/
Reported-by: syzbot+b4e65ca24fd4d0c734c3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000ac56fb06143b6cfa@google.com/
Reported-by: syzbot+d2b113dc9fea5e1d2848@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000000d69b206142d1ff7@google.com/
Reported-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000006f876b061478e878@google.com/
Tested-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Suggested-by: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Suggested-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Link: https://lore.kernel.org/r/20240328185801.1843078-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro()</title>
<updated>2024-07-05T07:37:56+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2024-03-08T05:38:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05412471beba313ecded95aa17b25fe84bb2551a'/>
<id>05412471beba313ecded95aa17b25fe84bb2551a</id>
<content type='text'>
[ Upstream commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 ]

set_memory_ro() can fail, leaving memory unprotected.

Check its return and take it into account as an error.

Link: https://github.com/KSPP/linux/issues/7
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: linux-hardening@vger.kernel.org &lt;linux-hardening@vger.kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Message-ID: &lt;286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 ]

set_memory_ro() can fail, leaving memory unprotected.

Check its return and take it into account as an error.

Link: https://github.com/KSPP/linux/issues/7
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: linux-hardening@vger.kernel.org &lt;linux-hardening@vger.kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Message-ID: &lt;286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
