From 18319cb478de23340fdcb6385b0cc074a5416da7 Mon Sep 17 00:00:00 2001
From: Jan Harkes <jaharkes@cs.cmu.edu>
Date: Mon, 8 Nov 2021 18:34:30 -0800
Subject: [PATCH] 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/coda/dir.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index d69989c1bac37..3fd085009f26d 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -499,15 +499,20 @@ static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
*/
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;
}
--
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