postgres.git / summary / log / commit / refs

commit    df0a67f754c2c45c99237765f30856c5dd95949d
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Thu Aug 06 17:25:45 2015 +0000

    Fix incorrect calculation in shm_mq_receive.
    
    If some, but not all, of the length word has already been read, and the
    next attempt to read sees exactly the number of bytes needed to complete
    the length word, or fewer, then we'll incorrectly read less than all of
    the available data.
    
    Antonin Houska


 src/backend/storage/ipc/shm_mq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/storage/ipc/shm_mq.c b/src/backend/storage/ipc/shm_mq.c
index 126cb0751b3..e765cea5aaa 100644
--- a/src/backend/storage/ipc/shm_mq.c
+++ b/src/backend/storage/ipc/shm_mq.c
@@ -584,7 +584,7 @@ shm_mq_receive(shm_mq_handle *mqh, Size *nbytesp, void **datap, bool nowait)
 			if (mqh->mqh_partial_bytes + rb > sizeof(Size))
 				lengthbytes = sizeof(Size) - mqh->mqh_partial_bytes;
 			else
-				lengthbytes = rb - mqh->mqh_partial_bytes;
+				lengthbytes = rb;
 			memcpy(&mqh->mqh_buffer[mqh->mqh_partial_bytes], rawdata,
 				   lengthbytes);
 			mqh->mqh_partial_bytes += lengthbytes;


[parent: 0e141c0fbb21]