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commit    c29022164f8a25d7b22763374c10a0c8311abcff
Author:   Daniel Gustafsson <dgustafsson@postgresql.org>
Date:     Tue Jan 30 10:15:46 2024 +0000
First released in: 17.0, 12.18, 13.14, 14.11, 15.6, 16.2

    pgcrypto: Fix check for buffer size
    
    The code copying the PGP block into the temp buffer failed to
    account for the extra 2 bytes in the buffer which are needed
    for the prefix. If the block was oversized, subsequent checks
    of the prefix would have exceeded the buffer size.  Since the
    block sizes are hardcoded in the list of supported ciphers it
    can be verified that there is no live bug here. Backpatch all
    the way for consistency though, as this bug is old.
    
    Author: Mikhail Gribkov <youzhick@gmail.com>
    Discussion: https://postgr.es/m/CAMEv5_uWvcMCMdRFDsJLz2Q8g16HEa9xWyfrkr+FYMMFJhawOw@mail.gmail.com
    Backpatch-through: v12


 contrib/pgcrypto/pgp-decrypt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/contrib/pgcrypto/pgp-decrypt.c b/contrib/pgcrypto/pgp-decrypt.c
index 7d8951cda41..965f4c92b20 100644
--- a/contrib/pgcrypto/pgp-decrypt.c
+++ b/contrib/pgcrypto/pgp-decrypt.c
@@ -250,7 +250,8 @@ prefix_init(void **priv_p, void *arg, PullFilter *src)
 	uint8		tmpbuf[PGP_MAX_BLOCK + 2];
 
 	len = pgp_get_cipher_block_size(ctx->cipher_algo);
-	if (len > sizeof(tmpbuf))
+	/* Make sure we have space for prefix */
+	if (len > PGP_MAX_BLOCK)
 		return PXE_BUG;
 
 	res = pullf_read_max(src, len + 2, &buf, tmpbuf);


[parent: dff1756c392e]