diff options
| author | Kees Cook <keescook@chromium.org> | 2023-07-26 14:59:57 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-07-27 08:48:12 -0700 |
| commit | 630fdd592912614a72d00026fdadad72d9ef62eb (patch) | |
| tree | c4a1e62c8c507c7793750416fecdd98eeef5203e /include/linux/seq_file.h | |
| parent | 8453e7924a1a9130f2b4d2c507de2cdc3892a5b5 (diff) | |
seq_file: seq_show_option_n() is used for precise sizes
When seq_show_option_n() is used, it is for non-string memory that
happens to be printable bytes. As such, we must use memcpy() to copy the
bytes and then explicitly NUL-terminate the result.
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230726215957.never.619-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include/linux/seq_file.h')
| -rw-r--r-- | include/linux/seq_file.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index bd023dd38ae6..386ab580b839 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -249,18 +249,19 @@ static inline void seq_show_option(struct seq_file *m, const char *name, /** * seq_show_option_n - display mount options with appropriate escapes - * where @value must be a specific length. + * where @value must be a specific length (i.e. + * not NUL-terminated). * @m: the seq_file handle * @name: the mount option name * @value: the mount option name's value, cannot be NULL - * @length: the length of @value to display + * @length: the exact length of @value to display, must be constant expression * * This is a macro since this uses "length" to define the size of the * stack buffer. */ #define seq_show_option_n(m, name, value, length) { \ char val_buf[length + 1]; \ - strncpy(val_buf, value, length); \ + memcpy(val_buf, value, length); \ val_buf[length] = '\0'; \ seq_show_option(m, name, val_buf); \ } |