From 12373ea918a0e72483662095686556eea21d67bc Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Wed, 19 Aug 2026 12:31:10 +0200 Subject: [PATCH] s390/boot: Bound command line facility ranges The facilities and debug-alternative command line parsers iterate over inclusive numeric ranges. If a range ends at ULONG_MAX, incrementing the current value wraps to zero and the loop never terminates. Large finite out-of-range values also cause unnecessary early boot iterations even though the bitmap helpers ignore them. Stop each loop at the size of the bitmap it modifies. This preserves all meaningful range values while guaranteeing termination. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens --- arch/s390/boot/alternative.c | 5 +++-- arch/s390/boot/ipl_parm.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/s390/boot/alternative.c b/arch/s390/boot/alternative.c index 19ea7934b918..77e8bad560c5 100644 --- a/arch/s390/boot/alternative.c +++ b/arch/s390/boot/alternative.c @@ -45,11 +45,12 @@ static void alt_debug_modify(int type, unsigned int nr, bool clear) static char *alt_debug_parse(int type, char *str) { - unsigned long val, endval; + unsigned long val, endval, limit; char *endp; bool clear; int i; + limit = type == ALT_TYPE_FACILITY ? MAX_FACILITY_BIT : MAX_MFEATURE_BIT; if (*str == ':') { str++; } else { @@ -73,7 +74,7 @@ static char *alt_debug_parse(int type, char *str) if (str == endp) break; str = endp; - while (val <= endval) { + while (val <= endval && val < limit) { alt_debug_modify(type, val, clear); val++; } diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c index 59eabf4a2de0..c1b43e5e688a 100644 --- a/arch/s390/boot/ipl_parm.c +++ b/arch/s390/boot/ipl_parm.c @@ -230,7 +230,7 @@ static void modify_fac_list(char *str) if (str == endp) break; str = endp; - while (val <= endval) { + while (val <= endval && val < MAX_FACILITY_BIT) { modify_facility(val, clear); val++; }