alexk / rpms / rpm

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commit 8f4b3c3cab8922a2022b9e47c71f1ecf906077ef
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Author: Demi Marie Obenour <athena@invisiblethingslab.com>
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Date:   Mon Feb 8 16:05:01 2021 -0500
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    hdrblobInit() needs bounds checks too
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    Users can pass untrusted data to hdrblobInit() and it must be robust
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    against this.
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diff --git a/lib/header.c b/lib/header.c
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index ea39e679f..ebba9c2b0 100644
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--- a/lib/header.c
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+++ b/lib/header.c
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@@ -11,6 +11,7 @@
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 #include "system.h"
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 #include <netdb.h>
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 #include <errno.h>
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+#include <inttypes.h>
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 #include <rpm/rpmtypes.h>
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 #include <rpm/rpmstring.h>
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 #include "lib/header_internal.h"
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@@ -1912,6 +1913,25 @@ hdrblob hdrblobFree(hdrblob blob)
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     return NULL;
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 }
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+static rpmRC hdrblobVerifyLengths(rpmTagVal regionTag, uint32_t il, uint32_t dl,
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+				  char **emsg) {
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+    uint32_t il_max = HEADER_TAGS_MAX;
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+    uint32_t dl_max = HEADER_DATA_MAX;
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+    if (regionTag == RPMTAG_HEADERSIGNATURES) {
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+	il_max = 32;
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+	dl_max = 64 * 1024 * 1024;
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+    }
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+    if (hdrchkRange(il_max, il)) {
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+	rasprintf(emsg, _("hdr tags: BAD, no. of tags(%" PRIu32 ") out of range"), il);
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+	return RPMRC_FAIL;
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+    }
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+    if (hdrchkRange(dl_max, dl)) {
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+	rasprintf(emsg, _("hdr data: BAD, no. of bytes(%" PRIu32 ") out of range"), dl);
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+	return RPMRC_FAIL;
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+    }
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+    return RPMRC_OK;
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+}
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+
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 rpmRC hdrblobRead(FD_t fd, int magic, int exact_size, rpmTagVal regionTag, hdrblob blob, char **emsg)
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 {
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     int32_t block[4];
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@@ -1924,13 +1944,6 @@ rpmRC hdrblobRead(FD_t fd, int magic, int exact_size, rpmTagVal regionTag, hdrbl
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     size_t nb;
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     rpmRC rc = RPMRC_FAIL;		/* assume failure */
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     int xx;
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-    int32_t il_max = HEADER_TAGS_MAX;
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-    int32_t dl_max = HEADER_DATA_MAX;
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-
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-    if (regionTag == RPMTAG_HEADERSIGNATURES) {
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-	il_max = 32;
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-	dl_max = 64 * 1024 * 1024;
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-    }
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     memset(block, 0, sizeof(block));
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     if ((xx = Freadall(fd, bs, blen)) != blen) {
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@@ -1943,15 +1956,9 @@ rpmRC hdrblobRead(FD_t fd, int magic, int exact_size, rpmTagVal regionTag, hdrbl
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 	goto exit;
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     }
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     il = ntohl(block[2]);
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-    if (hdrchkRange(il_max, il)) {
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-	rasprintf(emsg, _("hdr tags: BAD, no. of tags(%d) out of range"), il);
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-	goto exit;
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-    }
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     dl = ntohl(block[3]);
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-    if (hdrchkRange(dl_max, dl)) {
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-	rasprintf(emsg, _("hdr data: BAD, no. of bytes(%d) out of range"), dl);
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+    if (hdrblobVerifyLengths(regionTag, il, dl, emsg))
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 	goto exit;
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-    }
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     nb = (il * sizeof(struct entryInfo_s)) + dl;
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     uc = sizeof(il) + sizeof(dl) + nb;
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@@ -1995,11 +2002,18 @@ rpmRC hdrblobInit(const void *uh, size_t uc,
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 		struct hdrblob_s *blob, char **emsg)
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 {
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     rpmRC rc = RPMRC_FAIL;
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-
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     memset(blob, 0, sizeof(*blob));
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+    if (uc && uc < 8) {
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+	rasprintf(emsg, _("hdr length: BAD"));
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+	goto exit;
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+    }
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+
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     blob->ei = (int32_t *) uh; /* discards const */
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-    blob->il = ntohl(blob->ei[0]);
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-    blob->dl = ntohl(blob->ei[1]);
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+    blob->il = ntohl((uint32_t)(blob->ei[0]));
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+    blob->dl = ntohl((uint32_t)(blob->ei[1]));
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+    if (hdrblobVerifyLengths(regionTag, blob->il, blob->dl, emsg) != RPMRC_OK)
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+	goto exit;
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+
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     blob->pe = (entryInfo) &(blob->ei[2]);
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     blob->pvlen = sizeof(blob->il) + sizeof(blob->dl) +
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 		  (blob->il * sizeof(*blob->pe)) + blob->dl;