From 5f97ba0c74ccace0a4014460de9751ff3c6f454a Mon Sep 17 00:00:00 2001 From: Marc Hartmayer Date: Thu, 24 Sep 2020 10:59:24 +0200 Subject: pc-bios/s390-ccw: fix off-by-one error This error takes effect when the magic value "zIPL" is located at the end of a block. For example if s2_cur_blk = 0x7fe18000 and the magic value "zIPL" is located at 0x7fe18ffc - 0x7fe18fff. Fixes: ba831b25262a ("s390-ccw: read stage2 boot loader data to find menu") Reviewed-by: Collin Walling Signed-off-by: Marc Hartmayer Message-Id: <20200924085926.21709-2-mhartmay@linux.ibm.com> Reviewed-by: Thomas Huth [thuth: Use "<= ... - 4" instead of "< ... - 3"] Signed-off-by: Thomas Huth --- pc-bios/s390-ccw/bootmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c index 0ef6b85..767bb61 100644 --- a/pc-bios/s390-ccw/bootmap.c +++ b/pc-bios/s390-ccw/bootmap.c @@ -163,7 +163,7 @@ static bool find_zipl_boot_menu_banner(int *offset) int i; /* Menu banner starts with "zIPL" */ - for (i = 0; i < virtio_get_block_size() - 4; i++) { + for (i = 0; i <= virtio_get_block_size() - 4; i++) { if (magic_match(s2_cur_blk + i, ZIPL_MAGIC_EBCDIC)) { *offset = i; return true; -- cgit v1.1