[Cluster-devel] [PATCH] gfs2: Move a variable assignment behind a null pointer check in inode_go_dump()

[Markus Elfring]

Date: Thu, 13 Apr 2023 20:54:30 +0200

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “inode_go_dump”.

Thus avoid the risk for undefined behaviour by moving the assignment
for the variable “inode” behind the null pointer check.

This issue was detected by using the Coccinelle software.

Fixes: 27a2660f1ef944724956d92e8a312b6da0936fae ("gfs2: Dump nrpages for inodes 
and their glocks")
Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 fs/gfs2/glops.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index b65950e76be5..6e33c8058059 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -535,12 +535,13 @@ static void inode_go_dump(struct seq_file *seq, struct 
gfs2_glock *gl,
                          const char *fs_id_buf)
 {
        struct gfs2_inode *ip = gl->gl_object;
-       struct inode *inode = &ip->i_inode;
+       struct inode *inode;
        unsigned long nrpages;

        if (ip == NULL)
                return;

+       inode = &ip->i_inode;
        xa_lock_irq(&inode->i_data.i_pages);
        nrpages = inode->i_data.nrpages;
        xa_unlock_irq(&inode->i_data.i_pages);
--
2.40.0