The TAINT_RANDSTRUCT and TAINT_FWCTL flags are mistakenly set in the
taint_flags table as per-module flags. While this can be trivially
corrected, the issue can be avoided altogether by removing the
taint_flag.module field.

This is possible because, since commit 7fd8329ba502 ("taint/module: Clean
up global and module taint flags handling") in 2016, the handling of module
taint flags has been fully generic. Specifically, module_flags_taint() can
print all flags, and the required output buffer size is properly defined in
terms of TAINT_FLAGS_COUNT. The actual per-module flags are always those
added to module.taints by calls to add_taint_module().

Signed-off-by: Petr Pavlu <[email protected]>
---
The patch is based on linux-next (20251021) because I wanted to avoid
a conflict with "taint: add reminder about updating docs and scripts" [1],
which is currently queued in mm-nonmm-unstable.

[1] https://lore.kernel.org/all/[email protected]/

---
 include/linux/panic.h |  1 -
 kernel/module/main.c  |  2 +-
 kernel/panic.c        | 46 ++++++++++++++++++++-----------------------
 3 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/include/linux/panic.h b/include/linux/panic.h
index 6f972a66c13e..a00bc0937698 100644
--- a/include/linux/panic.h
+++ b/include/linux/panic.h
@@ -86,7 +86,6 @@ static inline void set_arch_panic_timeout(int timeout, int 
arch_default_timeout)
 struct taint_flag {
        char c_true;            /* character printed when tainted */
        char c_false;           /* character printed when not tainted */
-       bool module;            /* also show as a per-module taint flag */
        const char *desc;       /* verbose description of the set taint flag */
 };
 
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c66b26184936..6f219751df7e 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -954,7 +954,7 @@ size_t module_flags_taint(unsigned long taints, char *buf)
        int i;
 
        for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
-               if (taint_flags[i].module && test_bit(i, &taints))
+               if (test_bit(i, &taints))
                        buf[l++] = taint_flags[i].c_true;
        }
 
diff --git a/kernel/panic.c b/kernel/panic.c
index 81b7911fb5ca..341c66948dcb 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -628,17 +628,13 @@ void panic(const char *fmt, ...)
 }
 EXPORT_SYMBOL(panic);
 
-#define TAINT_FLAG(taint, _c_true, _c_false, _module)                  \
+#define TAINT_FLAG(taint, _c_true, _c_false)                           \
        [ TAINT_##taint ] = {                                           \
                .c_true = _c_true, .c_false = _c_false,                 \
-               .module = _module,                                      \
                .desc = #taint,                                         \
        }
 
 /*
- * TAINT_FORCED_RMMOD could be a per-module flag but the module
- * is being removed anyway.
- *
  * NOTE: if you modify the taint_flags or TAINT_FLAGS_COUNT,
  * please also modify tools/debugging/kernel-chktaint and
  * Documentation/admin-guide/tainted-kernels.rst, including its
@@ -646,26 +642,26 @@ EXPORT_SYMBOL(panic);
  * /proc/sys/kernel/tainted.
  */
 const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
-       TAINT_FLAG(PROPRIETARY_MODULE,          'P', 'G', true),
-       TAINT_FLAG(FORCED_MODULE,               'F', ' ', true),
-       TAINT_FLAG(CPU_OUT_OF_SPEC,             'S', ' ', false),
-       TAINT_FLAG(FORCED_RMMOD,                'R', ' ', false),
-       TAINT_FLAG(MACHINE_CHECK,               'M', ' ', false),
-       TAINT_FLAG(BAD_PAGE,                    'B', ' ', false),
-       TAINT_FLAG(USER,                        'U', ' ', false),
-       TAINT_FLAG(DIE,                         'D', ' ', false),
-       TAINT_FLAG(OVERRIDDEN_ACPI_TABLE,       'A', ' ', false),
-       TAINT_FLAG(WARN,                        'W', ' ', false),
-       TAINT_FLAG(CRAP,                        'C', ' ', true),
-       TAINT_FLAG(FIRMWARE_WORKAROUND,         'I', ' ', false),
-       TAINT_FLAG(OOT_MODULE,                  'O', ' ', true),
-       TAINT_FLAG(UNSIGNED_MODULE,             'E', ' ', true),
-       TAINT_FLAG(SOFTLOCKUP,                  'L', ' ', false),
-       TAINT_FLAG(LIVEPATCH,                   'K', ' ', true),
-       TAINT_FLAG(AUX,                         'X', ' ', true),
-       TAINT_FLAG(RANDSTRUCT,                  'T', ' ', true),
-       TAINT_FLAG(TEST,                        'N', ' ', true),
-       TAINT_FLAG(FWCTL,                       'J', ' ', true),
+       TAINT_FLAG(PROPRIETARY_MODULE,          'P', 'G'),
+       TAINT_FLAG(FORCED_MODULE,               'F', ' '),
+       TAINT_FLAG(CPU_OUT_OF_SPEC,             'S', ' '),
+       TAINT_FLAG(FORCED_RMMOD,                'R', ' '),
+       TAINT_FLAG(MACHINE_CHECK,               'M', ' '),
+       TAINT_FLAG(BAD_PAGE,                    'B', ' '),
+       TAINT_FLAG(USER,                        'U', ' '),
+       TAINT_FLAG(DIE,                         'D', ' '),
+       TAINT_FLAG(OVERRIDDEN_ACPI_TABLE,       'A', ' '),
+       TAINT_FLAG(WARN,                        'W', ' '),
+       TAINT_FLAG(CRAP,                        'C', ' '),
+       TAINT_FLAG(FIRMWARE_WORKAROUND,         'I', ' '),
+       TAINT_FLAG(OOT_MODULE,                  'O', ' '),
+       TAINT_FLAG(UNSIGNED_MODULE,             'E', ' '),
+       TAINT_FLAG(SOFTLOCKUP,                  'L', ' '),
+       TAINT_FLAG(LIVEPATCH,                   'K', ' '),
+       TAINT_FLAG(AUX,                         'X', ' '),
+       TAINT_FLAG(RANDSTRUCT,                  'T', ' '),
+       TAINT_FLAG(TEST,                        'N', ' '),
+       TAINT_FLAG(FWCTL,                       'J', ' '),
 };
 
 #undef TAINT_FLAG

base-commit: aaa9c3550b60d6259d6ea8b1175ade8d1242444e
-- 
2.51.1


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