Predict integer overflow to avoid buffer overruns.

Several functions, mostly type input functions, calculated an allocation
size such that the calculation wrapped to a small positive value when
arguments implied a sufficiently-large requirement.  Writes past the end
of the inadvertent small allocation followed shortly thereafter.
Coverity identified the path_in() vulnerability; code inspection led to
the rest.  In passing, add check_stack_depth() to prevent stack overflow
in related functions.

Back-patch to 8.4 (all supported versions).  The non-comment hstore
changes touch code that did not exist in 8.4, so that part stops at 9.0.

Noah Misch and Heikki Linnakangas, reviewed by Tom Lane.

Security: CVE-2014-0064

diff --git a/contrib/intarray/_int.h b/contrib/intarray/_int.h
index 35dbb54796f36e2ece52fb6c90118b885cdca8e1..f448ef11aada794d90f4ee294cdf25081266c023 100644 (file)
--- a/contrib/intarray/_int.h
+++ b/contrib/intarray/_int.h
@@ -5,6 +5,7 @@
 #define ___INT_H__
 
 #include "utils/array.h"
+#include "utils/memutils.h"
 
 /* number ranges for compression */
 #define MAXNUMRANGE 100
@@ -142,6 +143,7 @@ typedef struct
 
 #define HDRSIZEQT      (VARHDRSZ + sizeof(int4))
 #define COMPUTESIZE(size)      ( HDRSIZEQT + size * sizeof(ITEM) )
+#define QUERYTYPEMAXITEMS      ((MaxAllocSize - HDRSIZEQT) / sizeof(ITEM))
 #define GETQUERY(x)  (ITEM*)( (char*)(x)+HDRSIZEQT )
 
 #define END            0

diff --git a/contrib/intarray/_int_bool.c b/contrib/intarray/_int_bool.c
index 7a478faa83bacd23170b3d0b46857c7d3670d7ab..468a53a7bbbf536c6ab6212c3d70430499993f1c 100644 (file)
--- a/contrib/intarray/_int_bool.c
+++ b/contrib/intarray/_int_bool.c
@@ -416,6 +416,9 @@ boolop(PG_FUNCTION_ARGS)
 static void
 findoprnd(ITEM *ptr, int4 *pos)
 {
+       /* since this function recurses, it could be driven to stack overflow. */
+       check_stack_depth();
+
 #ifdef BS_DEBUG
        elog(DEBUG3, (ptr[*pos].type == OPR) ?
                 "%d  %c" : "%d  %d", *pos, ptr[*pos].val);
@@ -476,7 +479,13 @@ bqarr_in(PG_FUNCTION_ARGS)
                                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                                 errmsg("empty query")));
 
+       if (state.num > QUERYTYPEMAXITEMS)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+               errmsg("number of query items (%d) exceeds the maximum allowed (%d)",
+                          state.num, (int) QUERYTYPEMAXITEMS)));
        commonlen = COMPUTESIZE(state.num);
+
        query = (QUERYTYPE *) palloc(commonlen);
        SET_VARSIZE(query, commonlen);
        query->size = state.num;

diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index f16c6f9a32a06930267a9385087a6d6a8a72cc05..c3644e63ea0a4f524011d139b0b7d46d745bf27e 100644 (file)
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -6,6 +6,7 @@
 #include "postgres.h"
 #include "fmgr.h"
 #include "tsearch/ts_locale.h"
+#include "utils/memutils.h"
 
 typedef struct
 {
@@ -112,6 +113,8 @@ typedef struct
 
 #define HDRSIZEQT              MAXALIGN(VARHDRSZ + sizeof(int4))
 #define COMPUTESIZE(size,lenofoperand) ( HDRSIZEQT + (size) * sizeof(ITEM) + (lenofoperand) )
+#define LTXTQUERY_TOO_BIG(size,lenofoperand) \
+       ((size) > (MaxAllocSize - HDRSIZEQT - (lenofoperand)) / sizeof(ITEM))
 #define GETQUERY(x)  (ITEM*)( (char*)(x)+HDRSIZEQT )
 #define GETOPERAND(x)  ( (char*)GETQUERY(x) + ((ltxtquery*)x)->size * sizeof(ITEM) )
 

diff --git a/contrib/ltree/ltree_io.c b/contrib/ltree/ltree_io.c
index a88eb16cb97d506df3a9f87eb73d6a56fc9b9e65..f92e9aaa7ea55b7e5f28a7eea8cc1247053ac222 100644 (file)
--- a/contrib/ltree/ltree_io.c
+++ b/contrib/ltree/ltree_io.c
@@ -8,6 +8,7 @@
 #include <ctype.h>
 
 #include "ltree.h"
+#include "utils/memutils.h"
 #include "crc32.h"
 
 PG_FUNCTION_INFO_V1(ltree_in);
@@ -64,6 +65,11 @@ ltree_in(PG_FUNCTION_ARGS)
                ptr += charlen;
        }
 
+       if (num + 1 > MaxAllocSize / sizeof(nodeitem))
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                        errmsg("number of levels (%d) exceeds the maximum allowed (%d)",
+                                       num + 1, (int) (MaxAllocSize / sizeof(nodeitem)))));
        list = lptr = (nodeitem *) palloc(sizeof(nodeitem) * (num + 1));
        ptr = buf;
        while (*ptr)
@@ -228,6 +234,11 @@ lquery_in(PG_FUNCTION_ARGS)
        }
 
        num++;
+       if (num > MaxAllocSize / ITEMSIZE)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                        errmsg("number of levels (%d) exceeds the maximum allowed (%d)",
+                                       num, (int) (MaxAllocSize / ITEMSIZE))));
        curqlevel = tmpql = (lquery_level *) palloc0(ITEMSIZE * num);
        ptr = buf;
        while (*ptr)

diff --git a/contrib/ltree/ltxtquery_io.c b/contrib/ltree/ltxtquery_io.c
index d9163babf74807dbe72cd0b04b15d5d5e40b62eb..2cbcc89f5077d3b2d6577f3e4b8f5315d20ec202 100644 (file)
--- a/contrib/ltree/ltxtquery_io.c
+++ b/contrib/ltree/ltxtquery_io.c
@@ -9,6 +9,7 @@
 
 #include "crc32.h"
 #include "ltree.h"
+#include "miscadmin.h"
 
 PG_FUNCTION_INFO_V1(ltxtq_in);
 Datum          ltxtq_in(PG_FUNCTION_ARGS);
@@ -213,6 +214,9 @@ makepol(QPRS_STATE *state)
        int4            lenstack = 0;
        uint16          flag = 0;
 
+       /* since this function recurses, it could be driven to stack overflow */
+       check_stack_depth();
+
        while ((type = gettoken_query(state, &val, &lenval, &strval, &flag)) != END)
        {
                switch (type)
@@ -277,6 +281,9 @@ makepol(QPRS_STATE *state)
 static void
 findoprnd(ITEM *ptr, int4 *pos)
 {
+       /* since this function recurses, it could be driven to stack overflow. */
+       check_stack_depth();
+
        if (ptr[*pos].type == VAL || ptr[*pos].type == VALTRUE)
        {
                ptr[*pos].left = 0;
@@ -341,8 +348,12 @@ queryin(char *buf)
                                 errmsg("syntax error"),
                                 errdetail("Empty query.")));
 
-       /* make finish struct */
+       if (LTXTQUERY_TOO_BIG(state.num, state.sumlen))
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("ltxtquery is too large")));
        commonlen = COMPUTESIZE(state.num, state.sumlen);
+
        query = (ltxtquery *) palloc(commonlen);
        SET_VARSIZE(query, commonlen);
        query->size = state.num;

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index c1276b78c12d57c4076e631a3acbc13261e0ff6a..3ffab5eb2de4d5edc5ad3ffff74e450114bba77c 100644 (file)
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -1401,6 +1401,7 @@ path_in(PG_FUNCTION_ARGS)
        char       *s;
        int                     npts;
        int                     size;
+       int                     base_size;
        int                     depth = 0;
 
        if ((npts = pair_count(str, ',')) <= 0)
@@ -1419,7 +1420,15 @@ path_in(PG_FUNCTION_ARGS)
                depth++;
        }
 
-       size = offsetof(PATH, p[0]) +sizeof(path->p[0]) * npts;
+       base_size = sizeof(path->p[0]) * npts;
+       size = offsetof(PATH, p[0]) + base_size;
+
+       /* Check for integer overflow */
+       if (base_size / npts != sizeof(path->p[0]) || size <= base_size)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("too many points requested")));
+
        path = (PATH *) palloc(size);
 
        SET_VARSIZE(path, size);
@@ -3439,6 +3448,7 @@ poly_in(PG_FUNCTION_ARGS)
        POLYGON    *poly;
        int                     npts;
        int                     size;
+       int                     base_size;
        int                     isopen;
        char       *s;
 
@@ -3447,7 +3457,15 @@ poly_in(PG_FUNCTION_ARGS)
                                (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                          errmsg("invalid input syntax for type polygon: \"%s\"", str)));
 
-       size = offsetof(POLYGON, p[0]) +sizeof(poly->p[0]) * npts;
+       base_size = sizeof(poly->p[0]) * npts;
+       size = offsetof(POLYGON, p[0]) + base_size;
+
+       /* Check for integer overflow */
+       if (base_size / npts != sizeof(poly->p[0]) || size <= base_size)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("too many points requested")));
+
        poly = (POLYGON *) palloc0(size);       /* zero any holes */
 
        SET_VARSIZE(poly, size);
@@ -4216,6 +4234,10 @@ path_poly(PG_FUNCTION_ARGS)
                                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                                 errmsg("open path cannot be converted to polygon")));
 
+       /*
+        * Never overflows: the old size fit in MaxAllocSize, and the new size is
+        * just a small constant larger.
+        */
        size = offsetof(POLYGON, p[0]) +sizeof(poly->p[0]) * path->npts;
        poly = (POLYGON *) palloc(size);
 
@@ -4321,6 +4343,10 @@ poly_path(PG_FUNCTION_ARGS)
        int                     size;
        int                     i;
 
+       /*
+        * Never overflows: the old size fit in MaxAllocSize, and the new size is
+        * smaller by a small constant.
+        */
        size = offsetof(PATH, p[0]) +sizeof(path->p[0]) * poly->npts;
        path = (PATH *) palloc(size);
 

diff --git a/src/backend/utils/adt/tsquery.c b/src/backend/utils/adt/tsquery.c
index b8d8128de398b55c47391cbc64f1a9b60046ed05..e821f7924f8014dd3f0ddd18414262096db4fdcd 100644 (file)
--- a/src/backend/utils/adt/tsquery.c
+++ b/src/backend/utils/adt/tsquery.c
@@ -517,8 +517,13 @@ parse_tsquery(char *buf,
                return query;
        }
 
-       /* Pack the QueryItems in the final TSQuery struct to return to caller */
+       if (TSQUERY_TOO_BIG(list_length(state.polstr), state.sumlen))
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("tsquery is too large")));
        commonlen = COMPUTESIZE(list_length(state.polstr), state.sumlen);
+
+       /* Pack the QueryItems in the final TSQuery struct to return to caller */
        query = (TSQuery) palloc0(commonlen);
        SET_VARSIZE(query, commonlen);
        query->size = list_length(state.polstr);

diff --git a/src/backend/utils/adt/tsquery_util.c b/src/backend/utils/adt/tsquery_util.c
index d4a2ede1f627e5d6b5809c452b37514741d2f44f..dfe5779daf5d7ecde7a5df16312125a3d3146a38 100644 (file)
--- a/src/backend/utils/adt/tsquery_util.c
+++ b/src/backend/utils/adt/tsquery_util.c
@@ -334,6 +334,11 @@ QTN2QT(QTNode *in)
        QTN2QTState state;
 
        cntsize(in, &sumlen, &nnode);
+
+       if (TSQUERY_TOO_BIG(nnode, sumlen))
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("tsquery is too large")));
        len = COMPUTESIZE(nnode, sumlen);
 
        out = (TSQuery) palloc0(len);

diff --git a/src/backend/utils/adt/txid.c b/src/backend/utils/adt/txid.c
index a4a5b8667687c4d0abdfa0e7750664b6a9de4cfc..fa01b9a5fd43052d82eb68b55f219b1c9eaaf20b 100644 (file)
--- a/src/backend/utils/adt/txid.c
+++ b/src/backend/utils/adt/txid.c
@@ -26,6 +26,7 @@
 #include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "utils/builtins.h"
+#include "utils/memutils.h"
 #include "utils/snapmgr.h"
 
 
@@ -70,6 +71,8 @@ typedef struct
 
 #define TXID_SNAPSHOT_SIZE(nxip) \
        (offsetof(TxidSnapshot, xip) + sizeof(txid) * (nxip))
+#define TXID_SNAPSHOT_MAX_NXIP \
+       ((MaxAllocSize - offsetof(TxidSnapshot, xip)) / sizeof(txid))
 
 /*
  * Epoch values from xact.c
@@ -445,20 +448,12 @@ txid_snapshot_recv(PG_FUNCTION_ARGS)
        txid            last = 0;
        int                     nxip;
        int                     i;
-       int                     avail;
-       int                     expect;
        txid            xmin,
                                xmax;
 
-       /*
-        * load nxip and check for nonsense.
-        *
-        * (nxip > avail) check is against int overflows in 'expect'.
-        */
+       /* load and validate nxip */
        nxip = pq_getmsgint(buf, 4);
-       avail = buf->len - buf->cursor;
-       expect = 8 + 8 + nxip * 8;
-       if (nxip < 0 || nxip > avail || expect > avail)
+       if (nxip < 0 || nxip > TXID_SNAPSHOT_MAX_NXIP)
                goto bad_format;
 
        xmin = pq_getmsgint64(buf);

diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c
index aebc2baf1f512394ab4a97e467cd8a8e1764d685..3c15658c90fd5c459b948e483d904bc6800cd981 100644 (file)
--- a/src/backend/utils/adt/varbit.c
+++ b/src/backend/utils/adt/varbit.c
@@ -138,12 +138,22 @@ bit_in(PG_FUNCTION_ARGS)
                sp = input_string;
        }
 
+       /*
+        * Determine bitlength from input string.  MaxAllocSize ensures a regular
+        * input is small enough, but we must check hex input.
+        */
        slen = strlen(sp);
-       /* Determine bitlength from input string */
        if (bit_not_hex)
                bitlen = slen;
        else
+       {
+               if (slen > VARBITMAXLEN / 4)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("bit string length exceeds the maximum allowed (%d)",
+                                               VARBITMAXLEN)));
                bitlen = slen * 4;
+       }
 
        /*
         * Sometimes atttypmod is not supplied. If it is supplied we need to make
@@ -436,12 +446,22 @@ varbit_in(PG_FUNCTION_ARGS)
                sp = input_string;
        }
 
+       /*
+        * Determine bitlength from input string.  MaxAllocSize ensures a regular
+        * input is small enough, but we must check hex input.
+        */
        slen = strlen(sp);
-       /* Determine bitlength from input string */
        if (bit_not_hex)
                bitlen = slen;
        else
+       {
+               if (slen > VARBITMAXLEN / 4)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("bit string length exceeds the maximum allowed (%d)",
+                                               VARBITMAXLEN)));
                bitlen = slen * 4;
+       }
 
        /*
         * Sometimes atttypmod is not supplied. If it is supplied we need to make
@@ -520,6 +540,9 @@ varbit_in(PG_FUNCTION_ARGS)
 
 /* varbit_out -
  *       Prints the string as bits to preserve length accurately
+ *
+ * XXX varbit_recv() and hex input to varbit_in() can load a value that this
+ * cannot emit.  Consider using hex output for such values.
  */
 Datum
 varbit_out(PG_FUNCTION_ARGS)
@@ -886,6 +909,11 @@ bitcat(PG_FUNCTION_ARGS)
        bitlen1 = VARBITLEN(arg1);
        bitlen2 = VARBITLEN(arg2);
 
+       if (bitlen1 > VARBITMAXLEN - bitlen2)
+               ereport(ERROR,
+                               (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+                                errmsg("bit string length exceeds the maximum allowed (%d)",
+                                               VARBITMAXLEN)));
        bytelen = VARBITTOTALLEN(bitlen1 + bitlen2);
 
        result = (VarBit *) palloc(bytelen);

diff --git a/src/include/tsearch/ts_type.h b/src/include/tsearch/ts_type.h
index 60c16553eaf80e06e52ced3a6af611c114d0fa95..b9ca6cece604bbf14fd159f412c8cf3f539c10ec 100644 (file)
--- a/src/include/tsearch/ts_type.h
+++ b/src/include/tsearch/ts_type.h
@@ -13,6 +13,7 @@
 #define _PG_TSTYPE_H_
 
 #include "fmgr.h"
+#include "utils/memutils.h"
 #include "utils/pg_crc.h"
 
 
@@ -242,6 +243,8 @@ typedef TSQueryData *TSQuery;
  * QueryItems, and lenofoperand is the total length of all operands
  */
 #define COMPUTESIZE(size, lenofoperand) ( HDRSIZETQ + (size) * sizeof(QueryItem) + (lenofoperand) )
+#define TSQUERY_TOO_BIG(size, lenofoperand) \
+       ((size) > (MaxAllocSize - HDRSIZETQ - (lenofoperand)) / sizeof(QueryItem))
 
 /* Returns a pointer to the first QueryItem in a TSQuery */
 #define GETQUERY(x)  ((QueryItem*)( (char*)(x)+HDRSIZETQ ))

diff --git a/src/include/utils/varbit.h b/src/include/utils/varbit.h
index d316a0f093b6e1389dfa084f6a2bb8208592c1cd..c8dd5ede9cd40ae304dd8535ac5a5ca5832d2cfa 100644 (file)
--- a/src/include/utils/varbit.h
+++ b/src/include/utils/varbit.h
@@ -15,6 +15,8 @@
 #ifndef VARBIT_H
 #define VARBIT_H
 
+#include <limits.h>
+
 #include "fmgr.h"
 
 /*
@@ -53,6 +55,11 @@ typedef struct
 /* Number of bytes needed to store a bit string of a given length */
 #define VARBITTOTALLEN(BITLEN) (((BITLEN) + BITS_PER_BYTE-1)/BITS_PER_BYTE + \
                                                                 VARHDRSZ + VARBITHDRSZ)
+/*
+ * Maximum number of bits.  Several code sites assume no overflow from
+ * computing bitlen + X; VARBITTOTALLEN() has the largest such X.
+ */
+#define VARBITMAXLEN           (INT_MAX - BITS_PER_BYTE + 1)
 /* pointer beyond the end of the bit string (like end() in STL containers) */
 #define VARBITEND(PTR)         (((bits8 *) (PTR)) + VARSIZE(PTR))
 /* Mask that will cover exactly one byte, i.e. BITS_PER_BYTE bits */