This is a note to let you know that I've just added the patch titled SUNRPC: Fix READ_PLUS crasher to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sunrpc-fix-read_plus-crasher.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a23dd544debcda4ee4a549ec7de59e85c3c8345c Mon Sep 17 00:00:00 2001 From: Chuck Lever <chuck.lever@xxxxxxxxxx> Date: Thu, 30 Jun 2022 16:48:18 -0400 Subject: SUNRPC: Fix READ_PLUS crasher From: Chuck Lever <chuck.lever@xxxxxxxxxx> commit a23dd544debcda4ee4a549ec7de59e85c3c8345c upstream. Looks like there are still cases when "space_left - frag1bytes" can legitimately exceed PAGE_SIZE. Ensure that xdr->end always remains within the current encode buffer. Reported-by: Bruce Fields <bfields@xxxxxxxxxxxx> Reported-by: Zorro Lang <zlang@xxxxxxxxxx> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216151 Fixes: 6c254bf3b637 ("SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()") Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sunrpc/xdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -544,7 +544,7 @@ static __be32 *xdr_get_next_encode_buffe */ xdr->p = (void *)p + frag2bytes; space_left = xdr->buf->buflen - xdr->buf->len; - if (space_left - nbytes >= PAGE_SIZE) + if (space_left - frag1bytes >= PAGE_SIZE) xdr->end = (void *)p + PAGE_SIZE; else xdr->end = (void *)p + space_left - frag1bytes; Patches currently in stable-queue which might be from chuck.lever@xxxxxxxxxx are queue-4.19/sunrpc-fix-read_plus-crasher.patch