+ fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input.patch added to mm-nonmm-unstable branch

+ fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: fault-injection: enhance failcmd to exit on non-hex address input
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Breno Leitao <leitao@debian.org>
Subject: fault-injection: enhance failcmd to exit on non-hex address input
Date: Mon, 29 Jul 2024 01:45:08 -0700

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>
---

 tools/testing/fault-injection/failcmd.sh |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/tools/testing/fault-injection/failcmd.sh~fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input
+++ a/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
 		;;
_

Patches currently in -mm which might be from leitao@debian.org are

failcmd-add-script-file-in-maintainers.patch
fault-injection-enhance-failcmd-to-exit-on-non-hex-address-input.patch