The patch titled
Subject: alloc_tag: fix empty codetag module section handling
has been added to the -mm mm-unstable branch. Its filename is
alloc_tag-load-module-tags-into-separate-contiguous-memory-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alloc_tag-load-module-tags-into-separate-contiguous-memory-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: alloc_tag: fix empty codetag module section handling
Date: Thu, 31 Oct 2024 17:00:17 -0700
When a module does not have any allocations, it's allocation tag section
is empty and codetag_alloc_module_section() returns NULL. However this
condition should never happen because codetag_needs_module_section() will
detect an empty section and avoid calling codetag_alloc_module_section().
Change codetag_alloc_module_section() to never return NULL, which should
prevent static checker warnings. Add a WARN_ON() and a proper error
reporting in case codetag_alloc_module_section() returns NULL, to prevent
future codetag type implementations from returning NULL from their
cttype->desc.alloc_section_mem() operation.
Link: https://lkml.kernel.org/r/20241101000017.3856204-1-surenb@xxxxxxxxxx
Fixes: 61c9e58f3a10 ("alloc_tag: load module tags into separate contiguous memory")
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/50f12fa1-17c1-4940-a6bf-beaf61f6b17a@stanley.mountain/
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Daniel Gomez <da.gomez@xxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Petr Pavlu <petr.pavlu@xxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Thomas Huth <thuth@xxxxxxxxxx>
Cc: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/module/main.c | 4 ++++
lib/alloc_tag.c | 2 +-
lib/codetag.c | 2 +-
3 files changed, 6 insertions(+), 2 deletions(-)
--- a/kernel/module/main.c~alloc_tag-load-module-tags-into-separate-contiguous-memory-fix
+++ a/kernel/module/main.c
@@ -2316,6 +2316,10 @@ static int move_module(struct module *mo
if (codetag_needs_module_section(mod, sname, shdr->sh_size)) {
dest = codetag_alloc_module_section(mod, sname, shdr->sh_size,
arch_mod_section_prepend(mod, i), shdr->sh_addralign);
+ if (WARN_ON(!dest)) {
+ ret = -EINVAL;
+ goto out_err;
+ }
if (IS_ERR(dest)) {
ret = PTR_ERR(dest);
goto out_err;
--- a/lib/alloc_tag.c~alloc_tag-load-module-tags-into-separate-contiguous-memory-fix
+++ a/lib/alloc_tag.c
@@ -262,7 +262,7 @@ static void *reserve_module_tags(struct
/* If no tags return NULL */
if (size < sizeof(struct alloc_tag))
- return NULL;
+ return ERR_PTR(-EINVAL);
/*
* align is always power of 2, so we can use IS_ALIGNED and ALIGN.
--- a/lib/codetag.c~alloc_tag-load-module-tags-into-separate-contiguous-memory-fix
+++ a/lib/codetag.c
@@ -244,7 +244,7 @@ void *codetag_alloc_module_section(struc
{
const char *type_name = name + strlen(CODETAG_SECTION_PREFIX);
struct codetag_type *cttype;
- void *ret = NULL;
+ void *ret = ERR_PTR(-EINVAL);
mutex_lock(&codetag_lock);
list_for_each_entry(cttype, &codetag_types, link) {
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
maple_tree-add-mas_for_each_rev-helper.patch
alloc_tag-introduce-shutdown_mem_profiling-helper-function.patch
alloc_tag-load-module-tags-into-separate-contiguous-memory.patch
alloc_tag-load-module-tags-into-separate-contiguous-memory-fix.patch
alloc_tag-populate-memory-for-module-tags-as-needed.patch
alloc_tag-populate-memory-for-module-tags-as-needed-fix.patch
alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references.patch
alloc_tag-support-for-page-allocation-tag-compression.patch
mm-convert-mm_lock_seq-to-a-proper-seqcount.patch
mm-introduce-mmap_lock_speculation_beginend.patch
mm-codetag-uninline-and-move-pgalloc_tag_copy-and-pgalloc_tag_split.patch
