From e9dfcfb7b87107c2a55441c93aa463f9ea7586e1 Mon Sep 17 00:00:00 2001 From: Jeremy Harris Date: Thu, 12 Dec 2019 14:06:54 +0000 Subject: [PATCH] ARC: fix crash induced by misordered headers. Bug 2493 --- doc/doc-txt/ChangeLog | 3 +++ src/src/arc.c | 11 +++++------ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index 1de9571fb..1cc3d63c8 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -32,6 +32,9 @@ JH/08 Bug 2491: Use tainted buffers for the transport smtp context. Previously on-stack buffers were used, resulting in a taint trap when DSN information copied from a received message was written into the buffer. +JH/09 Bug 2493: Harden ARC verify against Outlook, whick has been seen to mix + the ordering of its ARC headers. This caused a crash. + Exim version 4.93 ----------------- diff --git a/src/src/arc.c b/src/src/arc.c index 857e0c046..94365498f 100644 --- a/src/src/arc.c +++ b/src/src/arc.c @@ -381,7 +381,7 @@ adding instances as needed and checking for duplicate lines. static uschar * arc_insert_hdr(arc_ctx * ctx, header_line * h, unsigned off, unsigned hoff, - BOOL instance_only) + BOOL instance_only, arc_line ** alp_ret) { unsigned i; arc_set * as; @@ -401,6 +401,7 @@ if (!(as = arc_find_set(ctx, i))) return US"set find"; if (*(alp = (arc_line **)(US as + hoff))) return US"dup hdr"; *alp = al; +if (alp_ret) *alp_ret = al; return NULL; } @@ -424,7 +425,7 @@ if (strncmpic(ARC_HDR_AAR, h->text, ARC_HDRLEN_AAR) == 0) debug_printf("ARC: found AAR: %.*s\n", len, h->text); } if ((e = arc_insert_hdr(ctx, h, ARC_HDRLEN_AAR, offsetof(arc_set, hdr_aar), - TRUE))) + TRUE, NULL))) { DEBUG(D_acl) debug_printf("inserting AAR: %s\n", e); return US"inserting AAR"; @@ -443,15 +444,13 @@ else if (strncmpic(ARC_HDR_AMS, h->text, ARC_HDRLEN_AMS) == 0) debug_printf("ARC: found AMS: %.*s\n", len, h->text); } if ((e = arc_insert_hdr(ctx, h, ARC_HDRLEN_AMS, offsetof(arc_set, hdr_ams), - instance_only))) + instance_only, &ams))) { DEBUG(D_acl) debug_printf("inserting AMS: %s\n", e); return US"inserting AMS"; } /* defaults */ - /*XXX dubious selection of ams here */ - ams = ctx->arcset_chain->hdr_ams; if (!ams->c.data) { ams->c_head.data = US"simple"; ams->c_head.len = 6; @@ -469,7 +468,7 @@ else if (strncmpic(ARC_HDR_AS, h->text, ARC_HDRLEN_AS) == 0) debug_printf("ARC: found AS: %.*s\n", len, h->text); } if ((e = arc_insert_hdr(ctx, h, ARC_HDRLEN_AS, offsetof(arc_set, hdr_as), - instance_only))) + instance_only, NULL))) { DEBUG(D_acl) debug_printf("inserting AS: %s\n", e); return US"inserting AS"; -- 2.30.2