Patch "mptcp: clean up harmless false expressions" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mptcp: clean up harmless false expressions

to the 5.15-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:
     mptcp-clean-up-harmless-false-expressions.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7e75809ad07ed61a034452901fccb24f7f30d974
Author: Jean Sacren <sakiwit@xxxxxxxxx>
Date:   Fri Dec 17 15:37:02 2021 -0800

    mptcp: clean up harmless false expressions
    
    [ Upstream commit 59060a47ca50bbdb1d863b73667a1065873ecc06 ]
    
    entry->addr.id is u8 with a range from 0 to 255 and MAX_ADDR_ID is 255.
    We should drop both false expressions of (entry->addr.id > MAX_ADDR_ID).
    
    We should also remove the obsolete parentheses in the first if branch.
    
    Use U8_MAX for MAX_ADDR_ID and add a comment to show the link to
    mptcp_addr_info.id as suggested by Mr. Matthieu Baerts.
    
    Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
    Signed-off-by: Jean Sacren <sakiwit@xxxxxxxxx>
    Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 3be10bf22cf7c..15c89d4fea4d2 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -38,7 +38,8 @@ struct mptcp_pm_add_entry {
 	u8			retrans_times;
 };
 
-#define MAX_ADDR_ID		255
+/* max value of mptcp_addr_info.id */
+#define MAX_ADDR_ID		U8_MAX
 #define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG)
 
 struct pm_nl_pernet {
@@ -831,14 +832,13 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 		entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 						    MAX_ADDR_ID + 1,
 						    pernet->next_id);
-		if ((!entry->addr.id || entry->addr.id > MAX_ADDR_ID) &&
-		    pernet->next_id != 1) {
+		if (!entry->addr.id && pernet->next_id != 1) {
 			pernet->next_id = 1;
 			goto find_next;
 		}
 	}
 
-	if (!entry->addr.id || entry->addr.id > MAX_ADDR_ID)
+	if (!entry->addr.id)
 		goto out;
 
 	__set_bit(entry->addr.id, pernet->id_bitmap);