From: Alexander Aring <aahringo@redhat.com>
Date: Mon, 1 Mar 2021 22:05:14 +0000 (-0500)
Subject: fs: dlm: change allocation limits
X-Git-Tag: accepted/tizen/unified/20230118.172025~7321^2~7
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c45674fbdda138814ca21138475219c96fa5aa1f;p=platform%2Fkernel%2Flinux-rpi.git

fs: dlm: change allocation limits

While running tcpkill I experienced invalid header length values while
receiving to check that a node doesn't try to send a invalid dlm message
we also check on applications minimum allocation limit. Also use
DEFAULT_BUFFER_SIZE as maximum allocation limit. The define
LOWCOMMS_MAX_TX_BUFFER_LEN is to calculate maximum buffer limits on
application layer, future midcomms layer will subtract their needs from
this define.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
---

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 4f2245e..206bd30 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -1376,9 +1376,11 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
 	struct writequeue_entry *e;
 	int offset = 0;
 
-	if (len > LOWCOMMS_MAX_TX_BUFFER_LEN) {
-		BUILD_BUG_ON(PAGE_SIZE < LOWCOMMS_MAX_TX_BUFFER_LEN);
+	if (len > DEFAULT_BUFFER_SIZE ||
+	    len < sizeof(struct dlm_header)) {
+		BUILD_BUG_ON(PAGE_SIZE < DEFAULT_BUFFER_SIZE);
 		log_print("failed to allocate a buffer of size %d", len);
+		WARN_ON(1);
 		return NULL;
 	}