diff options
| author | Thorsten Blum <thorsten.blum@linux.dev> | 2025-10-13 17:26:28 +0200 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko@kernel.org> | 2025-11-27 23:50:20 +0200 |
| commit | a0a76e3f8d9a0da679ea721decd26f8951eb2110 (patch) | |
| tree | c0db88489a3962cced83879a55ca22a928472d3d /security/keys/encrypted-keys | |
| parent | 58b46219bfcf1906b795307372b0d50d65115026 (diff) | |
keys: Replace deprecated strncpy in ecryptfs_fill_auth_tok
strncpy() is deprecated for NUL-terminated destination buffers; use
strscpy_pad() instead to retain the NUL-padding behavior of strncpy().
The destination buffer is initialized using kzalloc() with a 'signature'
size of ECRYPTFS_PASSWORD_SIG_SIZE + 1. strncpy() then copies up to
ECRYPTFS_PASSWORD_SIG_SIZE bytes from 'key_desc', NUL-padding any
remaining bytes if needed, but expects the last byte to be zero.
strscpy_pad() also copies the source string to 'signature', and NUL-pads
the destination buffer if needed, but ensures it's always NUL-terminated
without relying on it being zero-initialized.
strscpy_pad() automatically determines the size of the fixed-length
destination buffer via sizeof() when the optional size argument is
omitted, making an explicit size unnecessary.
In encrypted_init(), the source string 'key_desc' is validated by
valid_ecryptfs_desc() before calling ecryptfs_fill_auth_tok(), and is
therefore NUL-terminated and satisfies the __must_be_cstr() requirement
of strscpy_pad().
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'security/keys/encrypted-keys')
| -rw-r--r-- | security/keys/encrypted-keys/ecryptfs_format.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c index 8fdd76105ce3..2fc6f3a66135 100644 --- a/security/keys/encrypted-keys/ecryptfs_format.c +++ b/security/keys/encrypted-keys/ecryptfs_format.c @@ -54,8 +54,7 @@ int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) | ((uint16_t)minor & 0x00FF)); auth_tok->token_type = ECRYPTFS_PASSWORD; - strncpy((char *)auth_tok->token.password.signature, key_desc, - ECRYPTFS_PASSWORD_SIG_SIZE); + strscpy_pad(auth_tok->token.password.signature, key_desc); auth_tok->token.password.session_key_encryption_key_bytes = ECRYPTFS_MAX_KEY_BYTES; /* |