postgres.git / summary / log / commit / refs

commit    bd2843167200f2607972c0defb916daa79ca265f
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Oct 28 18:33:55 2024 +0000

    Guard against enormously long input in pg_saslprep().
    
    Coverity complained that pg_saslprep() could suffer integer overflow,
    leading to under-allocation of the output buffer, if the input string
    exceeds SIZE_MAX/4.  This hazard seems largely hypothetical, but it's
    easy enough to defend against, so let's do so.
    
    This patch creates a third place in src/common/ where we are locally
    defining MaxAllocSize so that we can test against that in the same way
    in backend and frontend compiles.  That seems like about two places
    too many, so the next patch will move that into common/fe_memutils.h.
    I'm hesitant to do that in back branches however.
    
    Back-patch to v14.  The code looks similar in older branches, but
    before commit 67a472d71 there was a separate test on the input string
    length that prevented this hazard.
    
    Per Coverity report.


 src/common/saslprep.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/common/saslprep.c b/src/common/saslprep.c
index 78f6fcbd805..0a840352802 100644
--- a/src/common/saslprep.c
+++ b/src/common/saslprep.c
@@ -21,8 +21,13 @@
  */
 #ifndef FRONTEND
 #include "postgres.h"
+#include "utils/memutils.h"
 #else
 #include "postgres_fe.h"
+
+/* It's possible we could use a different value for this in frontend code */
+#define MaxAllocSize	((Size) 0x3fffffff) /* 1 gigabyte - 1 */
+
 #endif
 
 #include "common/saslprep.h"
@@ -1079,6 +1084,8 @@ pg_saslprep(const char *input, char **output)
 	input_size = pg_utf8_string_len(input);
 	if (input_size < 0)
 		return SASLPREP_INVALID_UTF8;
+	if (input_size >= MaxAllocSize / sizeof(pg_wchar))
+		goto oom;
 
 	input_chars = ALLOC((input_size + 1) * sizeof(pg_wchar));
 	if (!input_chars)


[parent: 6cfb3a337469]