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From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-hardening@vger.kernel.org,
	Azeem Shaikh <azeemshaikh38@gmail.com>,
	linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org
Subject: [PATCH] m68k/atari: Replace strlcpy with strscpy
Date: Wed, 30 Aug 2023 18:54:28 +0000	[thread overview]
Message-ID: <20230830185428.4109426-1-azeemshaikh38@gmail.com> (raw)

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>
---
 arch/m68k/emu/natfeat.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/m68k/emu/natfeat.c b/arch/m68k/emu/natfeat.c
index b19dc00026d9..d124c62022c2 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -42,10 +42,10 @@ long nf_get_id(const char *feature_name)
 {
 	/* feature_name may be in vmalloc()ed memory, so make a copy */
 	char name_copy[32];
-	size_t n;
+	ssize_t n;

-	n = strlcpy(name_copy, feature_name, sizeof(name_copy));
-	if (n >= sizeof(name_copy))
+	n = strscpy(name_copy, feature_name, sizeof(name_copy));
+	if (n < 0)
 		return 0;

 	return nf_get_id_phys(virt_to_phys(name_copy));
--
2.42.0.283.g2d96d420d3-goog



             reply	other threads:[~2023-08-30 19:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-30 18:54 Azeem Shaikh [this message]
2023-08-31  0:04 ` [PATCH] m68k/atari: Replace strlcpy with strscpy Kees Cook
2023-09-04  9:29 ` Geert Uytterhoeven

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