5.10-stable review patch. If anyone has any objections, please let me know.
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From: Azeem Shaikh azeemshaikh38@gmail.com
[ Upstream commit babb80b3ecc6f40c962e13c654ebcd27f25ee327 ]
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh azeemshaikh38@gmail.com Reviewed-by: Kees Cook keescook@chromium.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/lrw.c | 6 +++--- crypto/xts.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/crypto/lrw.c b/crypto/lrw.c index bcf09fbc750af..80d9076e42e0b 100644 --- a/crypto/lrw.c +++ b/crypto/lrw.c @@ -357,10 +357,10 @@ static int lrw_create(struct crypto_template *tmpl, struct rtattr **tb) * cipher name. */ if (!strncmp(cipher_name, "ecb(", 4)) { - unsigned len; + int len;
- len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name)); - if (len < 2 || len >= sizeof(ecb_name)) + len = strscpy(ecb_name, cipher_name + 4, sizeof(ecb_name)); + if (len < 2) goto err_free_inst;
if (ecb_name[len - 1] != ')') diff --git a/crypto/xts.c b/crypto/xts.c index c6a105dba38b9..74dc199d54867 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -395,10 +395,10 @@ static int xts_create(struct crypto_template *tmpl, struct rtattr **tb) * cipher name. */ if (!strncmp(cipher_name, "ecb(", 4)) { - unsigned len; + int len;
- len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name)); - if (len < 2 || len >= sizeof(ctx->name)) + len = strscpy(ctx->name, cipher_name + 4, sizeof(ctx->name)); + if (len < 2) goto err_free_inst;
if (ctx->name[len - 1] != ')')