From: Breno Leitao <leitao@debian.org>
Date: Mon, 29 Jul 2024 08:45:08 +0000 (-0700)
Subject: fault-injection: enhance failcmd to exit on non-hex address input
X-Git-Tag: v6.12~389^2~64
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=11ee88a0f98770719f29b7d1efb2a2ca6a83af3c;p=platform%2Fkernel%2Flinux-amlogic.git

fault-injection: enhance failcmd to exit on non-hex address input

The failcmd.sh script in the fault-injection toolkit does not currently
validate whether the provided address is in hexadecimal format.  This can
lead to silent failures if the address is sourced from places like
`/proc/kallsyms`, which omits the '0x' prefix, potentially causing users
to operate under incorrect assumptions.

Introduce a new function, `exit_if_not_hex`, which checks the format of
the provided address and exits with an error message if the address is not
a valid hexadecimal number.

This enhancement prevents users from running the command with improperly
formatted addresses, thus improving the robustness and usability of the
failcmd tool.

Link: https://lkml.kernel.org/r/20240729084512.3349928-1-leitao@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/tools/testing/fault-injection/failcmd.sh b/tools/testing/fault-injection/failcmd.sh
index 78dac34264be..c4f2432750f4 100644
--- a/tools/testing/fault-injection/failcmd.sh
+++ b/tools/testing/fault-injection/failcmd.sh
@@ -64,6 +64,14 @@ ENVIRONMENT
 EOF
 }
 
+exit_if_not_hex() {
+    local value="$1"
+    if ! [[ $value =~ ^0x[0-9a-fA-F]+$ ]]; then
+        echo "Error: The provided value '$value' is not a valid hexadecimal number." >&2
+        exit 1
+    fi
+}
+
 if [ $UID != 0 ]; then
 	echo must be run as root >&2
 	exit 1
@@ -160,18 +168,22 @@ while true; do
 		shift 2
 		;;
 	--require-start)
+		exit_if_not_hex "$2"
 		echo $2 > $FAULTATTR/require-start
 		shift 2
 		;;
 	--require-end)
+		exit_if_not_hex "$2"
 		echo $2 > $FAULTATTR/require-end
 		shift 2
 		;;
 	--reject-start)
+		exit_if_not_hex "$2"
 		echo $2 > $FAULTATTR/reject-start
 		shift 2
 		;;
 	--reject-end)
+		exit_if_not_hex "$2"
 		echo $2 > $FAULTATTR/reject-end
 		shift 2
 		;;