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[57/87] coda: avoid NULL pointer dereference from a bad inode

Message ID 20211109023430.7SI-sYBYi%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [01/87] vfs: keep inodes with page cache off the inode shrinker LRU | expand

Commit Message

Andrew Morton Nov. 9, 2021, 2:34 a.m. UTC 
From: Jan Harkes <jaharkes@cs.cmu.edu>
Subject: coda: avoid NULL pointer dereference from a bad inode

Patch series "Coda updates for -next".

The following patch series contains some fixes for the Coda kernel module
I've had sitting around and were tested extensively in a development
version of the Coda kernel module that lives outside of the main kernel.


This patch (of 9):

Avoid accessing coda_inode_info from a dentry with a bad inode.

Link: https://lkml.kernel.org/r/20210908140308.18491-1-jaharkes@cs.cmu.edu
Link: https://lkml.kernel.org/r/20210908140308.18491-2-jaharkes@cs.cmu.edu
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jing Yangyang <jing.yangyang@zte.com.cn>
Cc: Xin Tan <tanxin.ctf@gmail.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/coda/dir.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)
diff mbox series

Patch

--- a/fs/coda/dir.c~coda-avoid-null-pointer-dereference-from-a-bad-inode
+++ a/fs/coda/dir.c
@@ -499,15 +499,20 @@  out:
  */
 static int coda_dentry_delete(const struct dentry * dentry)
 {
-	int flags;
+	struct inode *inode;
+	struct coda_inode_info *cii;
 
 	if (d_really_is_negative(dentry)) 
 		return 0;
 
-	flags = (ITOC(d_inode(dentry))->c_flags) & C_PURGE;
-	if (is_bad_inode(d_inode(dentry)) || flags) {
+	inode = d_inode(dentry);
+	if (!inode || is_bad_inode(inode))
 		return 1;
-	}
+
+	cii = ITOC(inode);
+	if (cii->c_flags & C_PURGE)
+		return 1;
+
 	return 0;
 }