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| author | Kees Cook <keescook@chromium.org> | 2021-05-19 12:16:59 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-05-19 15:06:13 -0700 |
| commit | 0bee95cae61e3cfc979fb3baab53189b65f5f777 (patch) | |
| tree | 75cc5ea4455e0e75bdf9e26fe24c9fe2c0d441f8 | |
| parent | 03404e22f4e88583981e087b1c28cd877f3f627a (diff) | |
| download | linux-0bee95cae61e3cfc979fb3baab53189b65f5f777.tar.gz | |
[DEBUG] fortify: Warn about all cases where memcpy() cannot check bounds
This is very noisy. :)
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | include/linux/fortify-string.h | 11 | ||||
| -rw-r--r-- | kernel/panic.c | 8 |
2 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index ed9b8b7c1cb00..74fd5ae241111 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -204,7 +204,7 @@ __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) * y = deterministic compile-time bounds checking * n = cannot do deterministic compile-time bounds checking * n/a = no run-time bounds checking needed since compile-time deterministic - * W = compile-time warn about lack of any bounds checking (TODO) + * W = compile-time warn about lack of any bounds checking * B = perform run-time bounds checking * */ @@ -251,6 +251,15 @@ __FORTIFY_INLINE void __fortify_memcpy_chk(void *p, const void *q, if (q_size != q_size_field) __runtime_read_check(); + /* + * Add build warnings to identify cases where it is + * not possible to perform run-time bounds checks. + */ + if (p_size == (size_t)(-1)) + __runtime_write_check_missing(); + if (q_size == (size_t)(-1)) + __runtime_read_check_missing(); + /* Warn when writing beyond destination field size. */ WARN_ON(p_size != p_size_field && p_size_field < size); /* Warn when reading beyond source field size. */ diff --git a/kernel/panic.c b/kernel/panic.c index 26257197162ed..bb29cda63e602 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -743,3 +743,11 @@ EXPORT_SYMBOL(__runtime_write_check); void __runtime_read_check(void) { } EXPORT_SYMBOL(__runtime_read_check); + +void __runtime_write_check_missing(void) +{ } +EXPORT_SYMBOL(__runtime_write_check_missing); + +void __runtime_read_check_missing(void) +{ } +EXPORT_SYMBOL(__runtime_read_check_missing); |