Added warnings in checkpatch.pl script to : 1. Deprecate strcpy() in favor of strscpy(). 2. Deprecate strlcpy() in favor of strscpy(). 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad(). Updated strncpy() section in Documentation/process/deprecated.rst to cover strscpy_pad() case. Signed-off-by: Nitin Gote <nitin.r.gote@xxxxxxxxx> --- This patch is already reviewed by mailing list kernel-hardening@xxxxxxxxxxxxxxxxxx. Refer below link <https://www.openwall.com/lists/kernel-hardening/2019/07/03/4> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Documentation/process/deprecated.rst | 6 +++--- scripts/checkpatch.pl | 5 +++++ 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst index 49e0f64..f564de3 100644 --- a/Documentation/process/deprecated.rst +++ b/Documentation/process/deprecated.rst @@ -93,9 +93,9 @@ will be NUL terminated. This can lead to various linear read overflows and other misbehavior due to the missing termination. It also NUL-pads the destination buffer if the source contents are shorter than the destination buffer size, which may be a needless performance penalty for callers using -only NUL-terminated strings. The safe replacement is :c:func:`strscpy`. -(Users of :c:func:`strscpy` still needing NUL-padding will need an -explicit :c:func:`memset` added.) +only NUL-terminated strings. In this case, the safe replacement is +:c:func:`strscpy`. If, however, the destination buffer still needs +NUL-padding, the safe replacement is :c:func:`strscpy_pad`. If a caller is using non-NUL-terminated strings, :c:func:`strncpy()` can still be used, but destinations should be marked with the `__nonstring diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 342c7c7..3d80967 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -595,6 +595,11 @@ our %deprecated_apis = ( "rcu_barrier_sched" => "rcu_barrier", "get_state_synchronize_sched" => "get_state_synchronize_rcu", "cond_synchronize_sched" => "cond_synchronize_rcu", + "strcpy" => "strscpy", + "strlcpy" => "strscpy", + "strncpy" => "strscpy, strscpy_pad or for + non-NUL-terminated strings, strncpy() can still be used, but + destinations should be marked with the __nonstring", ); #Create a search pattern for all these strings to speed up a loop below -- 2.7.4
