<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/kernel/pid.c, branch v6.18.21</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>Merge tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2025-09-29T18:20:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-09-29T18:20:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=18b19abc3709b109676ffd1f48dcd332c2e477d4'/>
<id>18b19abc3709b109676ffd1f48dcd332c2e477d4</id>
<content type='text'>
Pull namespace updates from Christian Brauner:
 "This contains a larger set of changes around the generic namespace
  infrastructure of the kernel.

  Each specific namespace type (net, cgroup, mnt, ...) embedds a struct
  ns_common which carries the reference count of the namespace and so
  on.

  We open-coded and cargo-culted so many quirks for each namespace type
  that it just wasn't scalable anymore. So given there's a bunch of new
  changes coming in that area I've started cleaning all of this up.

  The core change is to make it possible to correctly initialize every
  namespace uniformly and derive the correct initialization settings
  from the type of the namespace such as namespace operations, namespace
  type and so on. This leaves the new ns_common_init() function with a
  single parameter which is the specific namespace type which derives
  the correct parameters statically. This also means the compiler will
  yell as soon as someone does something remotely fishy.

  The ns_common_init() addition also allows us to remove ns_alloc_inum()
  and drops any special-casing of the initial network namespace in the
  network namespace initialization code that Linus complained about.

  Another part is reworking the reference counting. The reference
  counting was open-coded and copy-pasted for each namespace type even
  though they all followed the same rules. This also removes all open
  accesses to the reference count and makes it private and only uses a
  very small set of dedicated helpers to manipulate them just like we do
  for e.g., files.

  In addition this generalizes the mount namespace iteration
  infrastructure introduced a few cycles ago. As reminder, the vfs makes
  it possible to iterate sequentially and bidirectionally through all
  mount namespaces on the system or all mount namespaces that the caller
  holds privilege over. This allow userspace to iterate over all mounts
  in all mount namespaces using the listmount() and statmount() system
  call.

  Each mount namespace has a unique identifier for the lifetime of the
  systems that is exposed to userspace. The network namespace also has a
  unique identifier working exactly the same way. This extends the
  concept to all other namespace types.

  The new nstree type makes it possible to lookup namespaces purely by
  their identifier and to walk the namespace list sequentially and
  bidirectionally for all namespace types, allowing userspace to iterate
  through all namespaces. Looking up namespaces in the namespace tree
  works completely locklessly.

  This also means we can move the mount namespace onto the generic
  infrastructure and remove a bunch of code and members from struct
  mnt_namespace itself.

  There's a bunch of stuff coming on top of this in the future but for
  now this uses the generic namespace tree to extend a concept
  introduced first for pidfs a few cycles ago. For a while now we have
  supported pidfs file handles for pidfds. This has proven to be very
  useful.

  This extends the concept to cover namespaces as well. It is possible
  to encode and decode namespace file handles using the common
  name_to_handle_at() and open_by_handle_at() apis.

  As with pidfs file handles, namespace file handles are exhaustive,
  meaning it is not required to actually hold a reference to nsfs in
  able to decode aka open_by_handle_at() a namespace file handle.
  Instead the FD_NSFS_ROOT constant can be passed which will let the
  kernel grab a reference to the root of nsfs internally and thus decode
  the file handle.

  Namespaces file descriptors can already be derived from pidfds which
  means they aren't subject to overmount protection bugs. IOW, it's
  irrelevant if the caller would not have access to an appropriate
  /proc/&lt;pid&gt;/ns/ directory as they could always just derive the
  namespace based on a pidfd already.

  It has the same advantage as pidfds. It's possible to reliably and for
  the lifetime of the system refer to a namespace without pinning any
  resources and to compare them trivially.

  Permission checking is kept simple. If the caller is located in the
  namespace the file handle refers to they are able to open it otherwise
  they must hold privilege over the owning namespace of the relevant
  namespace.

  The namespace file handle layout is exposed as uapi and has a stable
  and extensible format. For now it simply contains the namespace
  identifier, the namespace type, and the inode number. The stable
  format means that userspace may construct its own namespace file
  handles without going through name_to_handle_at() as they are already
  allowed for pidfs and cgroup file handles"

* tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits)
  ns: drop assert
  ns: move ns type into struct ns_common
  nstree: make struct ns_tree private
  ns: add ns_debug()
  ns: simplify ns_common_init() further
  cgroup: add missing ns_common include
  ns: use inode initializer for initial namespaces
  selftests/namespaces: verify initial namespace inode numbers
  ns: rename to __ns_ref
  nsfs: port to ns_ref_*() helpers
  net: port to ns_ref_*() helpers
  uts: port to ns_ref_*() helpers
  ipv4: use check_net()
  net: use check_net()
  net-sysfs: use check_net()
  user: port to ns_ref_*() helpers
  time: port to ns_ref_*() helpers
  pid: port to ns_ref_*() helpers
  ipc: port to ns_ref_*() helpers
  cgroup: port to ns_ref_*() helpers
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull namespace updates from Christian Brauner:
 "This contains a larger set of changes around the generic namespace
  infrastructure of the kernel.

  Each specific namespace type (net, cgroup, mnt, ...) embedds a struct
  ns_common which carries the reference count of the namespace and so
  on.

  We open-coded and cargo-culted so many quirks for each namespace type
  that it just wasn't scalable anymore. So given there's a bunch of new
  changes coming in that area I've started cleaning all of this up.

  The core change is to make it possible to correctly initialize every
  namespace uniformly and derive the correct initialization settings
  from the type of the namespace such as namespace operations, namespace
  type and so on. This leaves the new ns_common_init() function with a
  single parameter which is the specific namespace type which derives
  the correct parameters statically. This also means the compiler will
  yell as soon as someone does something remotely fishy.

  The ns_common_init() addition also allows us to remove ns_alloc_inum()
  and drops any special-casing of the initial network namespace in the
  network namespace initialization code that Linus complained about.

  Another part is reworking the reference counting. The reference
  counting was open-coded and copy-pasted for each namespace type even
  though they all followed the same rules. This also removes all open
  accesses to the reference count and makes it private and only uses a
  very small set of dedicated helpers to manipulate them just like we do
  for e.g., files.

  In addition this generalizes the mount namespace iteration
  infrastructure introduced a few cycles ago. As reminder, the vfs makes
  it possible to iterate sequentially and bidirectionally through all
  mount namespaces on the system or all mount namespaces that the caller
  holds privilege over. This allow userspace to iterate over all mounts
  in all mount namespaces using the listmount() and statmount() system
  call.

  Each mount namespace has a unique identifier for the lifetime of the
  systems that is exposed to userspace. The network namespace also has a
  unique identifier working exactly the same way. This extends the
  concept to all other namespace types.

  The new nstree type makes it possible to lookup namespaces purely by
  their identifier and to walk the namespace list sequentially and
  bidirectionally for all namespace types, allowing userspace to iterate
  through all namespaces. Looking up namespaces in the namespace tree
  works completely locklessly.

  This also means we can move the mount namespace onto the generic
  infrastructure and remove a bunch of code and members from struct
  mnt_namespace itself.

  There's a bunch of stuff coming on top of this in the future but for
  now this uses the generic namespace tree to extend a concept
  introduced first for pidfs a few cycles ago. For a while now we have
  supported pidfs file handles for pidfds. This has proven to be very
  useful.

  This extends the concept to cover namespaces as well. It is possible
  to encode and decode namespace file handles using the common
  name_to_handle_at() and open_by_handle_at() apis.

  As with pidfs file handles, namespace file handles are exhaustive,
  meaning it is not required to actually hold a reference to nsfs in
  able to decode aka open_by_handle_at() a namespace file handle.
  Instead the FD_NSFS_ROOT constant can be passed which will let the
  kernel grab a reference to the root of nsfs internally and thus decode
  the file handle.

  Namespaces file descriptors can already be derived from pidfds which
  means they aren't subject to overmount protection bugs. IOW, it's
  irrelevant if the caller would not have access to an appropriate
  /proc/&lt;pid&gt;/ns/ directory as they could always just derive the
  namespace based on a pidfd already.

  It has the same advantage as pidfds. It's possible to reliably and for
  the lifetime of the system refer to a namespace without pinning any
  resources and to compare them trivially.

  Permission checking is kept simple. If the caller is located in the
  namespace the file handle refers to they are able to open it otherwise
  they must hold privilege over the owning namespace of the relevant
  namespace.

  The namespace file handle layout is exposed as uapi and has a stable
  and extensible format. For now it simply contains the namespace
  identifier, the namespace type, and the inode number. The stable
  format means that userspace may construct its own namespace file
  handles without going through name_to_handle_at() as they are already
  allowed for pidfs and cgroup file handles"

* tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits)
  ns: drop assert
  ns: move ns type into struct ns_common
  nstree: make struct ns_tree private
  ns: add ns_debug()
  ns: simplify ns_common_init() further
  cgroup: add missing ns_common include
  ns: use inode initializer for initial namespaces
  selftests/namespaces: verify initial namespace inode numbers
  ns: rename to __ns_ref
  nsfs: port to ns_ref_*() helpers
  net: port to ns_ref_*() helpers
  uts: port to ns_ref_*() helpers
  ipv4: use check_net()
  net: use check_net()
  net-sysfs: use check_net()
  user: port to ns_ref_*() helpers
  time: port to ns_ref_*() helpers
  pid: port to ns_ref_*() helpers
  ipc: port to ns_ref_*() helpers
  cgroup: port to ns_ref_*() helpers
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.18-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2025-09-29T17:02:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-09-29T17:02:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e571372101522fa91735dac6d30a160b2abe600c'/>
<id>e571372101522fa91735dac6d30a160b2abe600c</id>
<content type='text'>
Pull pidfs updates from Christian Brauner:
 "This just contains a few changes to pid_nr_ns() to make it more robust
  and cleans up or improves a few users that ab- or misuse it currently"

* tag 'vfs-6.18-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  pid: change task_state() to use task_ppid_nr_ns()
  pid: change bacct_add_tsk() to use task_ppid_nr_ns()
  pid: make __task_pid_nr_ns(ns =&gt; NULL) safe for zombie callers
  pid: Add a judgment for ns null in pid_nr_ns
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull pidfs updates from Christian Brauner:
 "This just contains a few changes to pid_nr_ns() to make it more robust
  and cleans up or improves a few users that ab- or misuse it currently"

* tag 'vfs-6.18-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  pid: change task_state() to use task_ppid_nr_ns()
  pid: change bacct_add_tsk() to use task_ppid_nr_ns()
  pid: make __task_pid_nr_ns(ns =&gt; NULL) safe for zombie callers
  pid: Add a judgment for ns null in pid_nr_ns
</pre>
</div>
</content>
</entry>
<entry>
<title>ns: move ns type into struct ns_common</title>
<updated>2025-09-25T07:23:54+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-24T11:33:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=4055526d35746ce8b04bfa5e14e14f28bb163186'/>
<id>4055526d35746ce8b04bfa5e14e14f28bb163186</id>
<content type='text'>
It's misplaced in struct proc_ns_operations and ns-&gt;ops might be NULL if
the namespace is compiled out but we still want to know the type of the
namespace for the initial namespace struct.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It's misplaced in struct proc_ns_operations and ns-&gt;ops might be NULL if
the namespace is compiled out but we still want to know the type of the
namespace for the initial namespace struct.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ns: use inode initializer for initial namespaces</title>
<updated>2025-09-19T14:22:38+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-19T09:29:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=7cf730321132e726ff949c6f3c0d5c598788f7a2'/>
<id>7cf730321132e726ff949c6f3c0d5c598788f7a2</id>
<content type='text'>
Just use the common helper we have.

Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Just use the common helper we have.

Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ns: rename to __ns_ref</title>
<updated>2025-09-19T14:22:38+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-18T10:11:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=024596a4e2802e457a9f92af79f246fa9631f8de'/>
<id>024596a4e2802e457a9f92af79f246fa9631f8de</id>
<content type='text'>
Make it easier to grep and rename to ns_count.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make it easier to grep and rename to ns_count.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pid: use ns_capable_noaudit() when determining net sysctl permissions</title>
<updated>2025-09-19T11:08:31+00:00</updated>
<author>
<name>Christian Göttsche</name>
<email>cgzones@googlemail.com</email>
</author>
<published>2025-09-10T19:26:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=b9cb7e59ac4ae68940347ebfc41e0436d32d3c6e'/>
<id>b9cb7e59ac4ae68940347ebfc41e0436d32d3c6e</id>
<content type='text'>
The capability check should not be audited since it is only being used
to determine the inode permissions. A failed check does not indicate a
violation of security policy but, when an LSM is enabled, a denial audit
message was being generated.

The denial audit message can either lead to the capability being
unnecessarily allowed in a security policy, or being silenced potentially
masking a legitimate capability check at a later point in time.

Similar to commit d6169b0206db ("net: Use ns_capable_noaudit() when
determining net sysctl permissions")

Fixes: 7863dcc72d0f ("pid: allow pid_max to be set per pid namespace")
CC: Christian Brauner &lt;brauner@kernel.org&gt;
CC: linux-security-module@vger.kernel.org
CC: selinux@vger.kernel.org
Signed-off-by: Christian Göttsche &lt;cgzones@googlemail.com&gt;
Acked-by: Serge Hallyn &lt;serge@hallyn.com&gt;
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The capability check should not be audited since it is only being used
to determine the inode permissions. A failed check does not indicate a
violation of security policy but, when an LSM is enabled, a denial audit
message was being generated.

The denial audit message can either lead to the capability being
unnecessarily allowed in a security policy, or being silenced potentially
masking a legitimate capability check at a later point in time.

Similar to commit d6169b0206db ("net: Use ns_capable_noaudit() when
determining net sysctl permissions")

Fixes: 7863dcc72d0f ("pid: allow pid_max to be set per pid namespace")
CC: Christian Brauner &lt;brauner@kernel.org&gt;
CC: linux-security-module@vger.kernel.org
CC: selinux@vger.kernel.org
Signed-off-by: Christian Göttsche &lt;cgzones@googlemail.com&gt;
Acked-by: Serge Hallyn &lt;serge@hallyn.com&gt;
Reviewed-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pid: make __task_pid_nr_ns(ns =&gt; NULL) safe for zombie callers</title>
<updated>2025-08-19T11:38:20+00:00</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@redhat.com</email>
</author>
<published>2025-08-10T17:36:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=abdfd4948e45c51b19162cf8b3f5003f8f53c9b9'/>
<id>abdfd4948e45c51b19162cf8b3f5003f8f53c9b9</id>
<content type='text'>
task_pid_vnr(another_task) will crash if the caller was already reaped.
The pid_alive(current) check can't really help, the parent/debugger can
call release_task() right after this check.

This also means that even task_ppid_nr_ns(current, NULL) is not safe,
pid_alive() only ensures that it is safe to dereference -&gt;real_parent.

Change __task_pid_nr_ns() to ensure ns != NULL.

Originally-by: 高翔 &lt;gaoxiang17@xiaomi.com&gt;
Link: https://lore.kernel.org/all/20250802022123.3536934-1-gxxa03070307@gmail.com/
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Link: https://lore.kernel.org/20250810173604.GA19991@redhat.com
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
task_pid_vnr(another_task) will crash if the caller was already reaped.
The pid_alive(current) check can't really help, the parent/debugger can
call release_task() right after this check.

This also means that even task_ppid_nr_ns(current, NULL) is not safe,
pid_alive() only ensures that it is safe to dereference -&gt;real_parent.

Change __task_pid_nr_ns() to ensure ns != NULL.

Originally-by: 高翔 &lt;gaoxiang17@xiaomi.com&gt;
Link: https://lore.kernel.org/all/20250802022123.3536934-1-gxxa03070307@gmail.com/
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Link: https://lore.kernel.org/20250810173604.GA19991@redhat.com
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pid: Add a judgment for ns null in pid_nr_ns</title>
<updated>2025-08-19T11:38:20+00:00</updated>
<author>
<name>gaoxiang17</name>
<email>gaoxiang17@xiaomi.com</email>
</author>
<published>2025-08-02T02:21:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=006568ab4c5ca2309ceb36fa553e390b4aa9c0c7'/>
<id>006568ab4c5ca2309ceb36fa553e390b4aa9c0c7</id>
<content type='text'>
__task_pid_nr_ns
        ns = task_active_pid_ns(current);
        pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
                if (pid &amp;&amp; ns-&gt;level &lt;= pid-&gt;level) {

Sometimes null is returned for task_active_pid_ns. Then it will trigger kernel panic in pid_nr_ns.

For example:
	Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
	Mem abort info:
	ESR = 0x0000000096000007
	EC = 0x25: DABT (current EL), IL = 32 bits
	SET = 0, FnV = 0
	EA = 0, S1PTW = 0
	FSC = 0x07: level 3 translation fault
	Data abort info:
	ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
	CM = 0, WnR = 0, TnD = 0, TagAccess = 0
	GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
	user pgtable: 4k pages, 39-bit VAs, pgdp=00000002175aa000
	[0000000000000058] pgd=08000002175ab003, p4d=08000002175ab003, pud=08000002175ab003, pmd=08000002175be003, pte=0000000000000000
	pstate: 834000c5 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
	pc : __task_pid_nr_ns+0x74/0xd0
	lr : __task_pid_nr_ns+0x24/0xd0
	sp : ffffffc08001bd10
	x29: ffffffc08001bd10 x28: ffffffd4422b2000 x27: 0000000000000001
	x26: ffffffd442821168 x25: ffffffd442821000 x24: 00000f89492eab31
	x23: 00000000000000c0 x22: ffffff806f5693c0 x21: ffffff806f5693c0
	x20: 0000000000000001 x19: 0000000000000000 x18: 0000000000000000
	x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 00000000023a1adc
	x14: 0000000000000003 x13: 00000000007ef6d8 x12: 001167c391c78800
	x11: 00ffffffffffffff x10: 0000000000000000 x9 : 0000000000000001
	x8 : ffffff80816fa3c0 x7 : 0000000000000000 x6 : 49534d702d535449
	x5 : ffffffc080c4c2c0 x4 : ffffffd43ee128c8 x3 : ffffffd43ee124dc
	x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffffff806f5693c0
	Call trace:
	__task_pid_nr_ns+0x74/0xd0
	...
	__handle_irq_event_percpu+0xd4/0x284
	handle_irq_event+0x48/0xb0
	handle_fasteoi_irq+0x160/0x2d8
	generic_handle_domain_irq+0x44/0x60
	gic_handle_irq+0x4c/0x114
	call_on_irq_stack+0x3c/0x74
	do_interrupt_handler+0x4c/0x84
	el1_interrupt+0x34/0x58
	el1h_64_irq_handler+0x18/0x24
	el1h_64_irq+0x68/0x6c
	account_kernel_stack+0x60/0x144
	exit_task_stack_account+0x1c/0x80
	do_exit+0x7e4/0xaf8
	...
	get_signal+0x7bc/0x8d8
	do_notify_resume+0x128/0x828
	el0_svc+0x6c/0x70
	el0t_64_sync_handler+0x68/0xbc
	el0t_64_sync+0x1a8/0x1ac
	Code: 35fffe54 911a02a8 f9400108 b4000128 (b9405a69)
	---[ end trace 0000000000000000 ]---
	Kernel panic - not syncing: Oops: Fatal exception in interrupt

Signed-off-by: gaoxiang17 &lt;gaoxiang17@xiaomi.com&gt;
Link: https://lore.kernel.org/20250802022123.3536934-1-gxxa03070307@gmail.com
Reviewed-by: Baoquan He &lt;bhe@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__task_pid_nr_ns
        ns = task_active_pid_ns(current);
        pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
                if (pid &amp;&amp; ns-&gt;level &lt;= pid-&gt;level) {

Sometimes null is returned for task_active_pid_ns. Then it will trigger kernel panic in pid_nr_ns.

For example:
	Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
	Mem abort info:
	ESR = 0x0000000096000007
	EC = 0x25: DABT (current EL), IL = 32 bits
	SET = 0, FnV = 0
	EA = 0, S1PTW = 0
	FSC = 0x07: level 3 translation fault
	Data abort info:
	ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
	CM = 0, WnR = 0, TnD = 0, TagAccess = 0
	GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
	user pgtable: 4k pages, 39-bit VAs, pgdp=00000002175aa000
	[0000000000000058] pgd=08000002175ab003, p4d=08000002175ab003, pud=08000002175ab003, pmd=08000002175be003, pte=0000000000000000
	pstate: 834000c5 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
	pc : __task_pid_nr_ns+0x74/0xd0
	lr : __task_pid_nr_ns+0x24/0xd0
	sp : ffffffc08001bd10
	x29: ffffffc08001bd10 x28: ffffffd4422b2000 x27: 0000000000000001
	x26: ffffffd442821168 x25: ffffffd442821000 x24: 00000f89492eab31
	x23: 00000000000000c0 x22: ffffff806f5693c0 x21: ffffff806f5693c0
	x20: 0000000000000001 x19: 0000000000000000 x18: 0000000000000000
	x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 00000000023a1adc
	x14: 0000000000000003 x13: 00000000007ef6d8 x12: 001167c391c78800
	x11: 00ffffffffffffff x10: 0000000000000000 x9 : 0000000000000001
	x8 : ffffff80816fa3c0 x7 : 0000000000000000 x6 : 49534d702d535449
	x5 : ffffffc080c4c2c0 x4 : ffffffd43ee128c8 x3 : ffffffd43ee124dc
	x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffffff806f5693c0
	Call trace:
	__task_pid_nr_ns+0x74/0xd0
	...
	__handle_irq_event_percpu+0xd4/0x284
	handle_irq_event+0x48/0xb0
	handle_fasteoi_irq+0x160/0x2d8
	generic_handle_domain_irq+0x44/0x60
	gic_handle_irq+0x4c/0x114
	call_on_irq_stack+0x3c/0x74
	do_interrupt_handler+0x4c/0x84
	el1_interrupt+0x34/0x58
	el1h_64_irq_handler+0x18/0x24
	el1h_64_irq+0x68/0x6c
	account_kernel_stack+0x60/0x144
	exit_task_stack_account+0x1c/0x80
	do_exit+0x7e4/0xaf8
	...
	get_signal+0x7bc/0x8d8
	do_notify_resume+0x128/0x828
	el0_svc+0x6c/0x70
	el0t_64_sync_handler+0x68/0xbc
	el0t_64_sync+0x1a8/0x1ac
	Code: 35fffe54 911a02a8 f9400108 b4000128 (b9405a69)
	---[ end trace 0000000000000000 ]---
	Kernel panic - not syncing: Oops: Fatal exception in interrupt

Signed-off-by: gaoxiang17 &lt;gaoxiang17@xiaomi.com&gt;
Link: https://lore.kernel.org/20250802022123.3536934-1-gxxa03070307@gmail.com
Reviewed-by: Baoquan He &lt;bhe@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl</title>
<updated>2025-07-30T04:43:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-07-30T04:43:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=4b290aae788e06561754b28c6842e4080957d3f7'/>
<id>4b290aae788e06561754b28c6842e4080957d3f7</id>
<content type='text'>
Pull sysctl updates from Joel Granados:

 - Move sysctls out of the kern_table array

   This is the final move of ctl_tables into their respective
   subsystems. Only 5 (out of the original 50) will remain in
   kernel/sysctl.c file; these handle either sysctl or common arch
   variables.

   By decentralizing sysctl registrations, subsystem maintainers regain
   control over their sysctl interfaces, improving maintainability and
   reducing the likelihood of merge conflicts.

 - docs: Remove false positives from check-sysctl-docs

   Stopped falsely identifying sysctls as undocumented or unimplemented
   in the check-sysctl-docs script. This script can now be used to
   automatically identify if documentation is missing.

* tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (23 commits)
  docs: Downgrade arm64 &amp; riscv from titles to comment
  docs: Replace spaces with tabs in check-sysctl-docs
  docs: Remove colon from ctltable title in vm.rst
  docs: Add awk section for ucount sysctl entries
  docs: Use skiplist when checking sysctl admin-guide
  docs: nixify check-sysctl-docs
  sysctl: rename kern_table -&gt; sysctl_subsys_table
  kernel/sys.c: Move overflow{uid,gid} sysctl into kernel/sys.c
  uevent: mv uevent_helper into kobject_uevent.c
  sysctl: Removed unused variable
  sysctl: Nixify sysctl.sh
  sysctl: Remove superfluous includes from kernel/sysctl.c
  sysctl: Remove (very) old file changelog
  sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.c
  sysctl: move cad_pid into kernel/pid.c
  sysctl: Move tainted ctl_table into kernel/panic.c
  Input: sysrq: mv sysrq into drivers/tty/sysrq.c
  fork: mv threads-max into kernel/fork.c
  parisc/power: Move soft-power into power.c
  mm: move randomize_va_space into memory.c
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull sysctl updates from Joel Granados:

 - Move sysctls out of the kern_table array

   This is the final move of ctl_tables into their respective
   subsystems. Only 5 (out of the original 50) will remain in
   kernel/sysctl.c file; these handle either sysctl or common arch
   variables.

   By decentralizing sysctl registrations, subsystem maintainers regain
   control over their sysctl interfaces, improving maintainability and
   reducing the likelihood of merge conflicts.

 - docs: Remove false positives from check-sysctl-docs

   Stopped falsely identifying sysctls as undocumented or unimplemented
   in the check-sysctl-docs script. This script can now be used to
   automatically identify if documentation is missing.

* tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (23 commits)
  docs: Downgrade arm64 &amp; riscv from titles to comment
  docs: Replace spaces with tabs in check-sysctl-docs
  docs: Remove colon from ctltable title in vm.rst
  docs: Add awk section for ucount sysctl entries
  docs: Use skiplist when checking sysctl admin-guide
  docs: nixify check-sysctl-docs
  sysctl: rename kern_table -&gt; sysctl_subsys_table
  kernel/sys.c: Move overflow{uid,gid} sysctl into kernel/sys.c
  uevent: mv uevent_helper into kobject_uevent.c
  sysctl: Removed unused variable
  sysctl: Nixify sysctl.sh
  sysctl: Remove superfluous includes from kernel/sysctl.c
  sysctl: Remove (very) old file changelog
  sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.c
  sysctl: move cad_pid into kernel/pid.c
  sysctl: Move tainted ctl_table into kernel/panic.c
  Input: sysrq: mv sysrq into drivers/tty/sysrq.c
  fork: mv threads-max into kernel/fork.c
  parisc/power: Move soft-power into power.c
  mm: move randomize_va_space into memory.c
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>sysctl: move cad_pid into kernel/pid.c</title>
<updated>2025-07-23T09:52:48+00:00</updated>
<author>
<name>Joel Granados</name>
<email>joel.granados@kernel.org</email>
</author>
<published>2025-05-05T19:47:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e054bcbe7e7af2baad3752f1a4916a7fffc0457e'/>
<id>e054bcbe7e7af2baad3752f1a4916a7fffc0457e</id>
<content type='text'>
Move cad_pid as well as supporting function proc_do_cad_pid into
kernel/pic.c. Replaced call to __do_proc_dointvec with proc_dointvec
inside proc_do_cad_pid which requires the copy of the ctl_table to
handle the temp value.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.

Reviewed-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Reviewed-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Joel Granados &lt;joel.granados@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move cad_pid as well as supporting function proc_do_cad_pid into
kernel/pic.c. Replaced call to __do_proc_dointvec with proc_dointvec
inside proc_do_cad_pid which requires the copy of the ctl_table to
handle the temp value.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.

Reviewed-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Reviewed-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Joel Granados &lt;joel.granados@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
