diff mbox series

cifs: avoid possible NULL dereference

Message ID 20230925045220.93400-1-suhui@nfschina.com (mailing list archive)
State New, archived
Headers show
Series cifs: avoid possible NULL dereference | expand

Commit Message

Su Hui Sept. 25, 2023, 4:52 a.m. UTC
smatch warn:
fs/smb/client/file.c:4910 cifs_oplock_break() warn:
variable dereferenced before check 'inode' (see line 4881)

If 'inode' is NULL, print some warning and return.

Signed-off-by: Su Hui <suhui@nfschina.com>
---
 fs/smb/client/file.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Dan Carpenter Sept. 25, 2023, 3:07 p.m. UTC | #1
On Mon, Sep 25, 2023 at 12:52:21PM +0800, Su Hui wrote:
> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
> index 2108b3b40ce9..37eed057ded0 100644
> --- a/fs/smb/client/file.c
> +++ b/fs/smb/client/file.c
> @@ -4878,6 +4878,12 @@ void cifs_oplock_break(struct work_struct *work)
>  	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
>  						  oplock_break);
>  	struct inode *inode = d_inode(cfile->dentry);
> +
> +	if (!inode) {
> +		cifs_dbg(FYI, "%s : failed to find inode\n", __func__);
> +		return;
> +	}
> +

Are we allowing this in the middle of the declaration block these days?

>  	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
>  	struct cifsInodeInfo *cinode = CIFS_I(inode);
>  	struct cifs_tcon *tcon;


regards,
dan carpenter
Su Hui Sept. 26, 2023, 1:20 a.m. UTC | #2
On 2023/9/25 23:07, Dan Carpenter wrote:
> On Mon, Sep 25, 2023 at 12:52:21PM +0800, Su Hui wrote:
>> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
>> index 2108b3b40ce9..37eed057ded0 100644
>> --- a/fs/smb/client/file.c
>> +++ b/fs/smb/client/file.c
>> @@ -4878,6 +4878,12 @@ void cifs_oplock_break(struct work_struct *work)
>>   	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
>>   						  oplock_break);
>>   	struct inode *inode = d_inode(cfile->dentry);
>> +
>> +	if (!inode) {
>> +		cifs_dbg(FYI, "%s : failed to find inode\n", __func__);
>> +		return;
>> +	}
>> +
> Are we allowing this in the middle of the declaration block these days?
Really sorry for this, I will modify it right now.
Thanks for your reminder!

Su Hui

>
>>   	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
>>   	struct cifsInodeInfo *cinode = CIFS_I(inode);
>>   	struct cifs_tcon *tcon;
>
> regards,
> dan carpenter
diff mbox series

Patch

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 2108b3b40ce9..37eed057ded0 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -4878,6 +4878,12 @@  void cifs_oplock_break(struct work_struct *work)
 	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
 						  oplock_break);
 	struct inode *inode = d_inode(cfile->dentry);
+
+	if (!inode) {
+		cifs_dbg(FYI, "%s : failed to find inode\n", __func__);
+		return;
+	}
+
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 	struct cifsInodeInfo *cinode = CIFS_I(inode);
 	struct cifs_tcon *tcon;
@@ -4907,7 +4913,7 @@  void cifs_oplock_break(struct work_struct *work)
 		cinode->oplock = 0;
 	}
 
-	if (inode && S_ISREG(inode->i_mode)) {
+	if (S_ISREG(inode->i_mode)) {
 		if (CIFS_CACHE_READ(cinode))
 			break_lease(inode, O_RDONLY);
 		else