From 3ddd6a650bd220252584fdd111fa284ed062363b Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Tue, 1 Feb 2011 19:25:08 +0000 Subject: [PATCH] The current libxl_set_memory_target function subtracts a negative amount from an uint32_t variable without checking if the operation wraps around. This patch fixes this bug (that I previously believed to be an hypervisor issue): http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1729 Signed-off-by: Stefano Stabellini Acked-by: Ian Jackson Committed-by: Ian Jackson --- tools/libxl/libxl.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 2d2b884baf..538932948d 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -2059,9 +2059,12 @@ retry_transaction: goto out; } - if (relative) - new_target_memkb = current_target_memkb + target_memkb; - else + if (relative) { + if (target_memkb < 0 && abs(target_memkb) > current_target_memkb) + new_target_memkb = 0; + else + new_target_memkb = current_target_memkb + target_memkb; + } else new_target_memkb = target_memkb; if (new_target_memkb > memorykb) { LIBXL__LOG(ctx, LIBXL__LOG_ERROR, -- 2.30.2