131 lines
3.5 KiB
Diff
131 lines
3.5 KiB
Diff
From 20c59ad54afc7427ea680f84c8ee5a576ba54b08 Mon Sep 17 00:00:00 2001
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From: Christos Zoulas <christos@zoulas.com>
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Date: Mon, 18 Apr 2016 15:10:34 +0000
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Subject: [PATCH] Downgrade DER comparison and offset lookup failures to be
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handled as match failures.
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---
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softmagic.c | 58 +++++++++++++++++++++++++++++++++++++++-------------------
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1 file changed, 39 insertions(+), 19 deletions(-)
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diff --git src/softmagic.c src/softmagic.c
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index 14a8bc5..5b5f0f9 100644
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--- src/softmagic.c
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+++ src/softmagic.c
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@@ -186,11 +186,11 @@ match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
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((text && (m->str_flags & FLT) == STRING_BINTEST) ||
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(!text && (m->str_flags & FLT) == STRING_TEXTTEST))) ||
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(m->flag & mode) != mode) {
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+flush:
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/* Skip sub-tests */
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- while (magindex + 1 < nmagic &&
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- magic[magindex + 1].cont_level != 0 &&
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- ++magindex)
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- continue;
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+ while (magindex < nmagic - 1 &&
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+ magic[magindex + 1].cont_level != 0)
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+ magindex++;
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continue; /* Skip to next top-level test*/
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}
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@@ -227,10 +227,7 @@ match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
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* main entry didn't match,
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* flush its continuations
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*/
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- while (magindex < nmagic - 1 &&
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- magic[magindex + 1].cont_level != 0)
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- magindex++;
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- continue;
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+ goto flush;
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}
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if ((e = handle_annotation(ms, m)) != 0) {
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@@ -255,8 +252,14 @@ match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
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if (print && mprint(ms, m) == -1)
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return -1;
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- if (moffset(ms, m, nbytes, &ms->c.li[cont_level].off) == -1)
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+ switch (moffset(ms, m, nbytes, &ms->c.li[cont_level].off)) {
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+ case -1:
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return -1;
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+ case 0:
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+ goto flush;
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+ default:
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+ break;
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+ }
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/* and any continuations that match */
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if (file_check_mem(ms, ++cont_level) == -1)
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@@ -362,9 +365,16 @@ match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
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if (print && mprint(ms, m) == -1)
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return -1;
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- if (moffset(ms, m, nbytes,
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- &ms->c.li[cont_level].off) == -1)
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+ switch (moffset(ms, m, nbytes,
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+ &ms->c.li[cont_level].off)) {
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+ case -1:
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return -1;
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+ case 0:
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+ flush = 1;
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+ break;
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+ default:
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+ break;
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+ }
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if (*m->desc)
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*need_separator = 1;
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@@ -813,9 +823,13 @@ moffset(struct magic_set *ms, struct magic *m, size_t nbytes, int32_t *op)
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case FILE_DER:
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{
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o = der_offs(ms, m, nbytes);
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- if (o == -1) {
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- file_error(ms, 0, "EOF computing DER offset");
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- return -1;
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+ if (o == -1 || (size_t)o > nbytes) {
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+ if ((ms->flags & MAGIC_DEBUG) != 0) {
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+ (void)fprintf(stderr,
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+ "Bad DER offset %d nbytes=%zu",
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+ o, nbytes);
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+ }
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+ return 0;
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}
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break;
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}
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@@ -825,12 +839,13 @@ moffset(struct magic_set *ms, struct magic *m, size_t nbytes, int32_t *op)
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break;
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}
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- if ((size_t)o >= nbytes) {
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- file_error(ms, 0, "Offset out of range");
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+ if ((size_t)o > nbytes) {
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+ file_error(ms, 0, "Offset out of range %zu > %zu",
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+ (size_t)o, nbytes);
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return -1;
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}
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*op = o;
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- return 0;
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+ return 1;
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}
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private uint32_t
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@@ -2107,8 +2122,13 @@ magiccheck(struct magic_set *ms, struct magic *m)
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return 1;
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case FILE_DER:
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matched = der_cmp(ms, m);
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- if (matched == -1)
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- file_error(ms, 0, "EOF comparing DER entries");
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+ if (matched == -1) {
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+ if ((ms->flags & MAGIC_DEBUG) != 0) {
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+ (void) fprintf(stderr,
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+ "EOF comparing DER entries");
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+ }
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+ return 0;
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+ }
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return matched;
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default:
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file_magerror(ms, "invalid type %d in magiccheck()", m->type);
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--
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2.6.6
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