From: Jan Beulich Date: Tue, 29 Apr 2025 09:56:44 +0000 (+0200) Subject: x86emul: also clip repetition count for STOS X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=9466bb1dc863485aee14808f787c95daa926490b;p=xen.git x86emul: also clip repetition count for STOS Like MOVS, INS, and OUTS, STOS also has a special purpose hook, where the hook function may legitimately have the same expectation as to the request not straddling address space start/end. Fixes: 5dfe4aa4eeb6 ("x86_emulate: Do not request emulation of REP instructions beyond the") Reported-by: Fabian Specht Signed-off-by: Jan Beulich Acked-by: Andrew Cooper master commit: 8c5636b6c87777e6c2e4ffae28bffe1cfc189bfd master date: 2025-04-22 11:24:20 +0200 --- diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c index 3d837f7e9e..b1d192cbbf 100644 --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -2217,7 +2217,7 @@ x86_emulate( dst.bytes = src.bytes; dst.mem.seg = x86_seg_es; - dst.mem.off = truncate_ea(_regs.r(di)); + dst.mem.off = truncate_ea_and_reps(_regs.r(di), nr_reps, dst.bytes); if ( (nr_reps == 1) || !ops->rep_stos || ((rc = ops->rep_stos(&src.val, dst.mem.seg, dst.mem.off, dst.bytes,