[merged mm-nonmm-stable] docsprocfs-document-proc-pid-access-permission-checks.patch removed from -mm tree

[merged mm-nonmm-stable] docsprocfs-document-proc-pid-access-permission-checks.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: docs,procfs: document /proc/PID/* access permission checks
has been removed from the -mm tree.  Its filename was
     docsprocfs-document-proc-pid-access-permission-checks.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Andrii Nakryiko <andrii@kernel.org>
Subject: docs,procfs: document /proc/PID/* access permission checks
Date: Tue, 28 Jan 2025 16:17:47 -0800

Add a paragraph explaining what sort of capabilities a process would need
to read procfs data for some other process.  Also mention that reading
data for its own process doesn't require any extra permissions.

Link: https://lkml.kernel.org/r/20250129001747.759990-1-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/filesystems/proc.rst |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/Documentation/filesystems/proc.rst~docsprocfs-document-proc-pid-access-permission-checks
+++ a/Documentation/filesystems/proc.rst
@@ -128,6 +128,16 @@ process running on the system, which is
 The link  'self'  points to  the process reading the file system. Each process
 subdirectory has the entries listed in Table 1-1.
 
+A process can read its own information from /proc/PID/* with no extra
+permissions. When reading /proc/PID/* information for other processes, reading
+process is required to have either CAP_SYS_PTRACE capability with
+PTRACE_MODE_READ access permissions, or, alternatively, CAP_PERFMON
+capability. This applies to all read-only information like `maps`, `environ`,
+`pagemap`, etc. The only exception is `mem` file due to its read-write nature,
+which requires CAP_SYS_PTRACE capabilities with more elevated
+PTRACE_MODE_ATTACH permissions; CAP_PERFMON capability does not grant access
+to /proc/PID/mem for other processes.
+
 Note that an open file descriptor to /proc/<pid> or to any of its
 contained files or subdirectories does not prevent <pid> being reused
 for some other process in the event that <pid> exits. Operations on
_

Patches currently in -mm which might be from andrii@kernel.org are