postgres.git / summary / log / commit / refs

commit    3bb339fa2c9f2bf09805170fe0867d83b562a324
Author:   Jacob Champion <jchampion@postgresql.org>
Date:     Fri Feb 06 19:09:09 2026 +0000

    Protect against small overread in SASLprep validation
    
    (This is a cherry-pick of 390b3cbbb, which I hadn't realized wasn't
    backpatched. It was originally reported to security@ and determined not
    to be a vulnerability; thanks to Stanislav Osipov for noticing the
    omission in the back branches.)
    
    In case of torn UTF8 in the input data we might end up going
    past the end of the string since we don't account for length.
    While validation won't be performed on a sequence with a NULL
    byte it's better to avoid going past the end to beging with.
    Fix by taking the length into consideration.
    
    Reported-by: Stanislav Osipov <stasos24@gmail.com>
    Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
    Discussion: https://postgr.es/m/CAOYmi+mTnmM172g=_+Yvc47hzzeAsYPy2C4UBY3HK9p-AXNV0g@mail.gmail.com
    Backpatch-through: 14


 src/common/saslprep.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/common/saslprep.c b/src/common/saslprep.c
index 0f224508d3f..7558b888edb 100644
--- a/src/common/saslprep.c
+++ b/src/common/saslprep.c
@@ -1009,15 +1009,17 @@ pg_utf8_string_len(const char *source)
 	const unsigned char *p = (const unsigned char *) source;
 	int			l;
 	int			num_chars = 0;
+	size_t		len = strlen(source);
 
-	while (*p)
+	while (len)
 	{
 		l = pg_utf_mblen(p);
 
-		if (!pg_utf8_islegal(p, l))
+		if (len < l || !pg_utf8_islegal(p, l))
 			return -1;
 
 		p += l;
+		len -= l;
 		num_chars++;
 	}
 


[parent: d32e17160971]