On 12/16/16 7:20 AM, Colin King wrote:
> From: Colin Ian King <colin.k...@canonical.com>
>
> inode is being deferenced and then inode is checked to see if it
> is null, implying we potentially could have a null pointer deference
> on inode.
>
> Found with static analysis by CoverityScan, CID 1389472
>
> Fix this by dereferencing inode only after the inode null check.
>
> Fixes: 0b246afa62b0cf5 ("btrfs: root->fs_info cleanup, add fs_info
> convenience variables")
Hi Colin -
Thanks for the review. The right fix here is to eliminate the tests for
inode == NULL entirely. This is a callback for exportfs, which will
itself crash if dentry->d_inode or parent->d_inode is NULL. Removing
the tests would be consistent with other file systems.
-Jeff
> Signed-off-by: Colin Ian King <colin.k...@canonical.com>
> ---
> fs/btrfs/export.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
> index 340d907..b746d2b 100644
> --- a/fs/btrfs/export.c
> +++ b/fs/btrfs/export.c
> @@ -223,7 +223,7 @@ static int btrfs_get_name(struct dentry *parent, char
> *name,
> {
> struct inode *inode = d_inode(child);
> struct inode *dir = d_inode(parent);
> - struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> + struct btrfs_fs_info *fs_info;
> struct btrfs_path *path;
> struct btrfs_root *root = BTRFS_I(dir)->root;
> struct btrfs_inode_ref *iref;
> @@ -241,6 +241,7 @@ static int btrfs_get_name(struct dentry *parent, char
> *name,
> if (!S_ISDIR(dir->i_mode))
> return -EINVAL;
>
> + fs_info = btrfs_sb(inode->i_sb);
> ino = btrfs_ino(inode);
>
> path = btrfs_alloc_path();
>
--
Jeff Mahoney
SUSE Labs
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