linux-kernel - [PATCH] Revert "arm64/sysreg: refactor deprecated strncpy"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230831162227.2307863-1-smostafa@google.com>
Date:   Thu, 31 Aug 2023 16:22:27 +0000
From:   Mostafa Saleh <smostafa@...gle.com>
To:     catalin.marinas@....com, will@...nel.org,
        linux-kernel@...r.kernel.org, kvmarm@...ts.linux.dev,
        linux-arm-kernel@...ts.infradead.org
Cc:     maz@...nel.org, oliver.upton@...ux.dev, kristina.martsenko@....com,
        broonie@...nel.org, quic_pkondeti@...cinc.com, smostafa@...gle.com,
        justinstitt@...gle.com
Subject: [PATCH] Revert "arm64/sysreg: refactor deprecated strncpy"

This reverts commit d232606773a0b09ec7f1ffc25f63abe801d011fd.

Using strscpy is not correct in this context and the commit
assumption is not right "strncpy is deprecated for use on
NUL-terminated destination strings".

strncpy is used here to copy parts of the string(cmdline) separated
by spaces into the buffer and not a NULL terminated string.

This breaks the arm options "kvm-arm.mode=protected, arm64.nobti ..."

Signed-off-by: Mostafa Saleh <smostafa@...gle.com>
---
 arch/arm64/kernel/idreg-override.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index aee12c75b738..2fe2491b692c 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -262,9 +262,9 @@ static __init void __parse_cmdline(const char *cmdline, bool parse_aliases)
 		if (!len)
 			return;
 
-		len = strscpy(buf, cmdline, ARRAY_SIZE(buf));
-		if (len == -E2BIG)
-			len = ARRAY_SIZE(buf) - 1;
+		len = min(len, ARRAY_SIZE(buf) - 1);
+		strncpy(buf, cmdline, len);
+		buf[len] = 0;
 
 		if (strcmp(buf, "--") == 0)
 			return;
-- 
2.42.0.rc2.253.gd59a3bf2b4-goog