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| author | Ard Biesheuvel <ardb@kernel.org> | 2026-09-09 10:10:03 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2026-10-04 21:53:56 +0200 |
| commit | 0f5a86b29fcc1c1f4e4be5d5899de52217ecd5be (patch) | |
| tree | d56a910e3a5eb1a3faf3fb5d0f5e9aa25aa95693 /include/linux | |
| parent | 4c0209bc31d26d1205fe0db29f33ce0290daf3d1 (diff) | |
| download | linux-0f5a86b29fcc1c1f4e4be5d5899de52217ecd5be.tar.gz linux-0f5a86b29fcc1c1f4e4be5d5899de52217ecd5be.zip | |
lib/ucs2_string: Split out ucs2_as_utf8_l() taking a separate limit
ucs2_as_utf8() takes a maxlength argument, which specifies how many
bytes the function is permitted to store into the destination buffer.
The same value is used as an upper bound for the ucs2_strnlen()
invocation, which is reasonable in the general case, as each UCS-2
character produces at least one byte of UTF-8 output, and so there is
never a need to process more than 'maxlength' UCS-2 characters.
However, if the UCS-2 string is not NUL terminated, ucs2_strnlen() may
read past the end of the buffer if 'maxlength' is set to a high value.
Current callers pass UCS-2 strings that are expected to be NUL
terminated, but for processing the load options in the EFI stub, a
version is needed that takes a separate limit argument. So split that
off from the current implementation.
Reviewed-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/ucs2_string.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h index c499ae809c7d..74f23ca5a967 100644 --- a/include/linux/ucs2_string.h +++ b/include/linux/ucs2_string.h @@ -14,7 +14,16 @@ ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count); int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len); unsigned long ucs2_utf8size(const ucs2_char_t *src); +unsigned long +ucs2_as_utf8_l(u8 *dest, const ucs2_char_t *src, unsigned long limit, + unsigned long maxlength); + +static inline unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, - unsigned long maxlength); + unsigned long maxlength) +{ + return ucs2_as_utf8_l(dest, src, ucs2_strnlen(src, maxlength), + maxlength); +} #endif /* _LINUX_UCS2_STRING_H_ */ |