afs: Fix storage of cell names

[ Upstream commit 719fdd32921fb7e3208db8832d32ae1c2d68900f ]

The cell name stored in the afs_cell struct is a 64-char + NUL buffer -
when it needs to be able to handle up to AFS_MAXCELLNAME (256 chars) + NUL.

Fix this by changing the array to a pointer and allocating the string.

Found using Coverity.

Fixes: 989782dcdc91 ("afs: Overhaul cell database management")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 78ba5f9322879ebdb7449806fbdc1cf2c2595887..296b489861a9a831be2e52a2cf5479906da1b01d 100644 (file)
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -154,10 +154,17 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
                return ERR_PTR(-ENOMEM);
        }
 
+       cell->name = kmalloc(namelen + 1, GFP_KERNEL);
+       if (!cell->name) {
+               kfree(cell);
+               return ERR_PTR(-ENOMEM);
+       }
+
        cell->net = net;
        cell->name_len = namelen;
        for (i = 0; i < namelen; i++)
                cell->name[i] = tolower(name[i]);
+       cell->name[i] = 0;
 
        atomic_set(&cell->usage, 2);
        INIT_WORK(&cell->manager, afs_manage_cell);
@@ -203,6 +210,7 @@ parse_failed:
        if (ret == -EINVAL)
                printk(KERN_ERR "kAFS: bad VL server IP address\n");
 error:
+       kfree(cell->name);
        kfree(cell);
        _leave(" = %d", ret);
        return ERR_PTR(ret);
@@ -483,6 +491,7 @@ static void afs_cell_destroy(struct rcu_head *rcu)
 
        afs_put_vlserverlist(cell->net, rcu_access_pointer(cell->vl_servers));
        key_put(cell->anonymous_key);
+       kfree(cell->name);
        kfree(cell);
 
        _leave(" [destroyed]");

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 555ad7c9afcb6ad08be6b07a9793a13f32114459..7fe88d918b23857c51821e25596945a3f667662d 100644 (file)
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -397,7 +397,7 @@ struct afs_cell {
        struct afs_vlserver_list __rcu *vl_servers;
 
        u8                      name_len;       /* Length of name */
-       char                    name[64 + 1];   /* Cell name, case-flattened and NUL-padded */
+       char                    *name;          /* Cell name, case-flattened and NUL-padded */
 };
 
 /*