drivers/of/overlay: Use memcpy() to copy known length strings
PATCH 1/1 drivers/of/overlay: Use memcpy() to copy known length strings
From: David Laight <[email protected]>
The lengths have been used for the kzalloc(), use the same ones for the copy.
---
This is one of a group of patches that remove potentially unbounded strcpy() calls.
They are mostly replaced by strscpy() or, when strlen() has just been called, with memcpy() (usually including the '\0').
Calls with copy string literals into arrays are left unchanged. They are safe and easily detected as such.
The changes were made by getting the compiler to detect the calls and then fixing the code by hand.
Note that all the changes are only compile tested.
Some Makefiles were changed to allow files to contain strcpy(). As well as 'difficult to fix' files, this included 'show' functions as they really need to use sysfs_emit() or seq_printf().
All the patches are being sent individually to avoid very long cc lists. Apologies for the terse commit messages and likely unexpected tags. (There are about 100 patches in total.)
drivers/of/overlay.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/of/overlay.c +2 -2
@@ -258,8 +258,8 @@ static struct property *dup_and_fixup_symbol_prop(if (!new_prop->name || !new_prop->value) goto err_free_new_prop; -strcpy (new_prop->value, target_path); -strcpy (new_prop->value + target_path_len, path_tail); +memcpy (new_prop->value, target_path, target_path_len); +memcpy (new_prop->value + target_path_len, path_tail, path_tail_len);of_property_set_flag (new_prop,OF_DYNAMIC );
Signature · 1 line
2.39.5
Rob Herring
maintainerQuoted 4 lines · On Mon, Jun 8, 2026 at 4:55 AM <[email protected]> wrote:
From: David Laight <[email protected]>
The lengths have been used for the
kzalloc(), use the same ones for the copy.
This doesn't answer why we are doing this. Only the below which gets removed on commit provides the reasoning.
Quoted 46 lines
Signed-off-by David Laight <[email protected]>---
This is one of a group of patches that remove potentially unboundedstrcpy()calls.They are mostly replaced by
strscpy()or, whenstrlen()has just been called, withmemcpy()(usually including the '\0').Calls with copy string literals into arrays are left unchanged. They are safe and easily detected as such.
The changes were made by getting the compiler to detect the calls and then fixing the code by hand.
Note that all the changes are only compile tested.
Some Makefiles were changed to allow files to contain
strcpy(). As well as 'difficult to fix' files, this included 'show' functions as they really need to usesysfs_emit()orseq_printf().All the patches are being sent individually to avoid very long cc lists. Apologies for the terse commit messages and likely unexpected tags. (There are about 100 patches in total.)
drivers/of/overlay.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)drivers/of/overlay.c +2
-3@@ -258,8 +258,8 @@ static struct property *dup_and_fixup_symbol_prop(if (!new_prop->name || !new_prop->value) goto err_free_new_prop; -strcpy (new_prop->value, target_path); -strcpy (new_prop->value + target_path_len, path_tail); +memcpy (new_prop->value, target_path, target_path_len); +memcpy (new_prop->value + target_path_len, path_tail, path_tail_len);of_property_set_flag (new_prop,OF_DYNAMIC ); --2.39.5
Quoted 8 lines · On Mon, 8 Jun 2026 12:35:06 -0500 Rob Herring <[email protected]> wrote:
Quoted 4 lines · On Mon, Jun 8, 2026 at 4:55 AM <[email protected]> wrote:
From: David Laight <[email protected]>
The lengths have been used for the
kzalloc(), use the same ones for the copy.This doesn't answer why we are doing this. Only the below which gets removed on commit provides the reasoning.
I will resend with an extra line (or two) of description above the ---.
(I was using -m 'text' to add the commit message and using same text for equivalent changes to multiple files - seem to have got caught out!)
-- David
Quoted 47 lines
Quoted 47 lines
Signed-off-by David Laight <[email protected]>---
This is one of a group of patches that remove potentially unboundedstrcpy()calls.They are mostly replaced by
strscpy()or, whenstrlen()has just been called, withmemcpy()(usually including the '\0').Calls with copy string literals into arrays are left unchanged. They are safe and easily detected as such.
The changes were made by getting the compiler to detect the calls and then fixing the code by hand.
Note that all the changes are only compile tested.
Some Makefiles were changed to allow files to contain
strcpy(). As well as 'difficult to fix' files, this included 'show' functions as they really need to usesysfs_emit()orseq_printf().All the patches are being sent individually to avoid very long cc lists. Apologies for the terse commit messages and likely unexpected tags. (There are about 100 patches in total.)
drivers/of/overlay.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)drivers/of/overlay.c +2
-3@@ -258,8 +258,8 @@ static struct property *dup_and_fixup_symbol_prop(if (!new_prop->name || !new_prop->value) goto err_free_new_prop; -strcpy (new_prop->value, target_path); -strcpy (new_prop->value + target_path_len, path_tail); +memcpy (new_prop->value, target_path, target_path_len); +memcpy (new_prop->value + target_path_len, path_tail, path_tail_len);of_property_set_flag (new_prop,OF_DYNAMIC ); --2.39.5