Date: Tue, 25 Oct 2016 17:13:46 +0000 (UTC) From: Gleb Smirnoff <glebius@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r307936 - head/sys/amd64/amd64 Message-ID: <201610251713.u9PHDkq2076226@repo.freebsd.org>
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Author: glebius Date: Tue Oct 25 17:13:46 2016 New Revision: 307936 URL: https://svnweb.freebsd.org/changeset/base/307936 Log: The argument validation in r296956 was not enough to close all possible overflows in sysarch(2). Submitted by: Kun Yang <kun.yang chaitin.com> Patch by: kib Security: SA-16:15 Modified: head/sys/amd64/amd64/sys_machdep.c Modified: head/sys/amd64/amd64/sys_machdep.c ============================================================================== --- head/sys/amd64/amd64/sys_machdep.c Tue Oct 25 17:11:20 2016 (r307935) +++ head/sys/amd64/amd64/sys_machdep.c Tue Oct 25 17:13:46 2016 (r307936) @@ -608,6 +608,8 @@ amd64_set_ldt(td, uap, descs) largest_ld = uap->start + uap->num; if (largest_ld > max_ldt_segment) largest_ld = max_ldt_segment; + if (largest_ld < uap->start) + return (EINVAL); i = largest_ld - uap->start; mtx_lock(&dt_lock); bzero(&((struct user_segment_descriptor *)(pldt->ldt_base)) @@ -620,7 +622,8 @@ amd64_set_ldt(td, uap, descs) /* verify range of descriptors to modify */ largest_ld = uap->start + uap->num; if (uap->start >= max_ldt_segment || - largest_ld > max_ldt_segment) + largest_ld > max_ldt_segment || + largest_ld < uap->start) return (EINVAL); }
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