linux.git/kernel/module, branch v6.18.21

module: Fix kernel panic when a symbol st_shndx is out of bounds

2026-04-02T11:22:58+00:00

[ Upstream commit f9d69d5e7bde2295eb7488a56f094ac8f5383b92 ]

The module loader doesn't check for bounds of the ELF section index in
simplify_symbols():

       for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

		switch (sym[i].st_shndx) {
		case SHN_COMMON:

		[...]

		default:
			/* Divert to percpu allocation if a percpu var. */
			if (sym[i].st_shndx == info->index.pcpu)
				secbase = (unsigned long)mod_percpu(mod);
			else
  /** HERE --> **/		secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
			sym[i].st_value += secbase;
			break;
		}
	}

A symbol with an out-of-bounds st_shndx value, for example 0xffff
(known as SHN_XINDEX or SHN_HIRESERVE), may cause a kernel panic:

  BUG: unable to handle page fault for address: ...
  RIP: 0010:simplify_symbols+0x2b2/0x480
  ...
  Kernel panic - not syncing: Fatal exception

This can happen when module ELF is legitimately using SHN_XINDEX or
when it is corrupted.

Add a bounds check in simplify_symbols() to validate that st_shndx is
within the valid range before using it.

This issue was discovered due to a bug in llvm-objcopy, see relevant
discussion for details [1].

[1] https://lore.kernel.org/linux-modules/20251224005752.201911-1-ihor.solodrai@linux.dev/

Signed-off-by: Ihor Solodrai 
Reviewed-by: Daniel Gomez 
Reviewed-by: Petr Pavlu 
Signed-off-by: Sami Tolvanen 
Signed-off-by: Sasha Levin

module: Remove duplicate freeing of lockdep classes

2026-03-12T11:09:47+00:00

[ Upstream commit a7b4bc094fbaa7dc7b7b91ae33549bbd7eefaac1 ]

In the error path of load_module(), under the free_module label, the
code calls lockdep_free_key_range() to release lock classes associated
with the MOD_DATA, MOD_RODATA and MOD_RO_AFTER_INIT module regions, and
subsequently invokes module_deallocate().

Since commit ac3b43283923 ("module: replace module_layout with
module_memory"), the module_deallocate() function calls free_mod_mem(),
which releases the lock classes as well and considers all module
regions.

Attempting to free these classes twice is unnecessary. Remove the
redundant code in load_module().

Fixes: ac3b43283923 ("module: replace module_layout with module_memory")
Signed-off-by: Petr Pavlu 
Reviewed-by: Daniel Gomez 
Reviewed-by: Aaron Tomlin 
Acked-by: Song Liu 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Sami Tolvanen 
Signed-off-by: Sasha Levin

module: add helper function for reading module_buildid()

2026-02-26T22:59:17+00:00

[ Upstream commit acfdbb4ab2910ff6f03becb569c23ac7b2223913 ]

Add a helper function for reading the optional "build_id" member of struct
module.  It is going to be used also in ftrace_mod_address_lookup().

Use "#ifdef" instead of "#if IS_ENABLED()" to match the declaration of the
optional field in struct module.

Link: https://lkml.kernel.org/r/20251128135920.217303-4-pmladek@suse.com
Signed-off-by: Petr Mladek 
Reviewed-by: Daniel Gomez 
Reviewed-by: Petr Pavlu 
Cc: Aaron Tomlin 
Cc: Alexei Starovoitov 
Cc: Daniel Borkman 
Cc: John Fastabend 
Cc: Kees Cook 
Cc: Luis Chamberalin 
Cc: Marc Rutland 
Cc: "Masami Hiramatsu (Google)" 
Cc: Sami Tolvanen 
Cc: Steven Rostedt (Google) 
Signed-off-by: Andrew Morton 
Stable-dep-of: e8a1e7eaa19d ("kallsyms/ftrace: set module buildid in ftrace_mod_address_lookup()")
Signed-off-by: Sasha Levin

kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI

2025-09-24T21:29:14+00:00

The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).

Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.

Reviewed-by: Linus Walleij 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook

Merge tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-05T13:02:07+00:00

Pull more MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "mseal cleanups" (Lorenzo Stoakes)

     Some mseal cleaning with no intended functional change.

   - "Optimizations for khugepaged" (David Hildenbrand)

     Improve khugepaged throughput by batching PTE operations for large
     folios. This gain is mainly for arm64.

   - "x86: enable EXECMEM_ROX_CACHE for ftrace and kprobes" (Mike Rapoport)

     A bugfix, additional debug code and cleanups to the execmem code.

   - "mm/shmem, swap: bugfix and improvement of mTHP swap in" (Kairui Song)

     Bugfixes, cleanups and performance improvememnts to the mTHP swapin
     code"

* tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (38 commits)
  mm: mempool: fix crash in mempool_free() for zero-minimum pools
  mm: correct type for vmalloc vm_flags fields
  mm/shmem, swap: fix major fault counting
  mm/shmem, swap: rework swap entry and index calculation for large swapin
  mm/shmem, swap: simplify swapin path and result handling
  mm/shmem, swap: never use swap cache and readahead for SWP_SYNCHRONOUS_IO
  mm/shmem, swap: tidy up swap entry splitting
  mm/shmem, swap: tidy up THP swapin checks
  mm/shmem, swap: avoid redundant Xarray lookup during swapin
  x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations
  x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations
  execmem: drop writable parameter from execmem_fill_trapping_insns()
  execmem: add fallback for failures in vmalloc(VM_ALLOW_HUGE_VMAP)
  execmem: move execmem_force_rw() and execmem_restore_rox() before use
  execmem: rework execmem_cache_free()
  execmem: introduce execmem_alloc_rw()
  execmem: drop unused execmem_update_copy()
  mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped
  mm/rmap: add anon_vma lifetime debug check
  mm: remove mm/io-mapping.c
  ...

execmem: introduce execmem_alloc_rw()

2025-08-02T19:06:11+00:00

Some callers of execmem_alloc() require the memory to be temporarily
writable even when it is allocated from ROX cache.  These callers use
execemem_make_temp_rw() right after the call to execmem_alloc().

Wrap this sequence in execmem_alloc_rw() API.

Link: https://lkml.kernel.org/r/20250713071730.4117334-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Reviewed-by: Daniel Gomez 
Reviewed-by: Petr Pavlu 
Acked-by: Peter Zijlstra (Intel) 
Cc: Masami Hiramatsu (Google) 
Cc: Steven Rostedt (Google) 
Signed-off-by: Andrew Morton

module: Remove unnecessary +1 from last_unloaded_module::name size

2025-07-31T11:57:32+00:00

The variable last_unloaded_module::name tracks the name of the last
unloaded module. It is a string copy of module::name, which is
MODULE_NAME_LEN bytes in size and includes the NUL terminator. Therefore,
the size of last_unloaded_module::name can also be just MODULE_NAME_LEN,
without the need for an extra byte.

Fixes: e14af7eeb47e ("debug: track and print last unloaded module in the oops trace")
Signed-off-by: Petr Pavlu 
Reviewed-by: Daniel Gomez 
Link: https://lore.kernel.org/r/20250630143535.267745-3-petr.pavlu@suse.com
Signed-off-by: Daniel Gomez

module: Prevent silent truncation of module name in delete_module(2)

2025-07-31T11:57:21+00:00

Passing a module name longer than MODULE_NAME_LEN to the delete_module
syscall results in its silent truncation. This really isn't much of
a problem in practice, but it could theoretically lead to the removal of an
incorrect module. It is more sensible to return ENAMETOOLONG or ENOENT in
such a case.

Update the syscall to return ENOENT, as documented in the delete_module(2)
man page to mean "No module by that name exists." This is appropriate
because a module with a name longer than MODULE_NAME_LEN cannot be loaded
in the first place.

Signed-off-by: Petr Pavlu 
Reviewed-by: Daniel Gomez 
Link: https://lore.kernel.org/r/20250630143535.267745-2-petr.pavlu@suse.com
Signed-off-by: Daniel Gomez

module: move 'struct module_use' to internal.h

2025-07-31T11:40:46+00:00

The struct was moved to the public header file in commit c8e21ced08b3
("module: fix kdb's illicit use of struct module_use.").
Back then the structure was used outside of the module core.
Nowadays this is not true anymore, so the structure can be made internal.

Signed-off-by: Thomas Weißschuh 
Reviewed-by: Daniel Gomez 
Reviewed-by: Petr Pavlu 
Link: https://lore.kernel.org/r/20250711-kunit-ifdef-modules-v2-1-39443decb1f8@linutronix.de
Signed-off-by: Daniel Gomez

Merge tag 'ftrace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-07-30T23:04:10+00:00

Pull ftrace updates from Steven Rostedt:

 - Keep track of when fgraph_ops are registered or not

   Keep accounting of when fgraph_ops are registered as if a fgraph_ops
   is registered twice it can mess up the accounting and it will not
   work as expected later. Trigger a warning if something registers it
   twice as to catch bugs before they are found by things just not
   working as expected.

 - Make DYNAMIC_FTRACE always enabled for architectures that support it

   As static ftrace (where all functions are always traced) is very
   expensive and only exists to help architectures support ftrace, do
   not make it an option. As soon as an architecture supports
   DYNAMIC_FTRACE make it use it. This simplifies the code.

 - Remove redundant config HAVE_FTRACE_MCOUNT_RECORD

   The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
   DYNAMIC_FTRACE work, but now every architecture that implements
   DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it
   redundant with the HAVE_DYNAMIC_FTRACE.

 - Make pid_ptr string size match the comment

   In print_graph_proc() the pid_ptr string is of size 11, but the
   comment says /* sign + log10(MAX_INT) + '\0' */ which is actually 12.

* tag 'ftrace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
  ftrace: Make DYNAMIC_FTRACE always enabled for architectures that support it
  fgraph: Keep track of when fgraph_ops are registered or not
  fgraph: Make pid_str size match the comment