afs: Fix missing/incorrect unlocking of RCU read lock

dhowells · dhowells · commit b90493505347 · 2024-01-22T22:30:38.000Z
In afs_proc_addr_prefs_show(), we need to unlock the RCU read lock in both places before returning (and not lock it again). Fixes: f94f70d ("afs: Provide a way to configure address priorities") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202401172243.cd53d5f6-oliver.sang@intel.com Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
@@ -166,7 +166,7 @@ static int afs_proc_addr_prefs_show(struct seq_file *m, void *v)
 
 	if (!preflist) {
 		seq_puts(m, "NO PREFS\n");
-		return 0;
+		goto out;
 	}
 
 	seq_printf(m, "PROT SUBNET                                      PRIOR (v=%u n=%u/%u/%u)\n",
@@ -191,7 +191,8 @@ static int afs_proc_addr_prefs_show(struct seq_file *m, void *v)
 		}
 	}
 
-	rcu_read_lock();
+out:
+	rcu_read_unlock();
 	return 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -166,7 +166,7 @@ static int afs_proc_addr_prefs_show(struct seq_file m, void v)`
`166`	`166`
`167`	`167`	`if (!preflist) {`
`168`	`168`	`seq_puts(m, "NO PREFS\n");`
`169`		`- return 0;`
	`169`	`+ goto out;`
`170`	`170`	`}`
`171`	`171`
`172`	`172`	`seq_printf(m, "PROT SUBNET PRIOR (v=%u n=%u/%u/%u)\n",`
`@@ -191,7 +191,8 @@ static int afs_proc_addr_prefs_show(struct seq_file m, void v)`
`191`	`191`	`}`
`192`	`192`	`}`
`193`	`193`
`194`		`- rcu_read_lock();`
	`194`	`+out:`
	`195`	`+ rcu_read_unlock();`
`195`	`196`	`return 0;`
`196`	`197`	`}`
`197`	`198`