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authorAmir Goldstein2020-03-02 15:03:35 +0200
committerMiklos Szeredi2020-03-12 16:38:10 +0100
commit531d3040bc5cf37dea01b118608347cca9325f9d (patch)
treecebd4580264859afc1d17ec86a9ce44710708db9
parent11a48a5a18c63fd7621bb050228cebf13566e4d8 (diff)
ovl: fix lock in ovl_llseek()
ovl_inode_lock() is interruptible. When inode_lock() in ovl_llseek() was replaced with ovl_inode_lock(), we did not add a check for error. Fix this by making ovl_inode_lock() uninterruptible and change the existing call sites to use an _interruptible variant. Reported-by: syzbot+66a9752fa927f745385e@syzkaller.appspotmail.com Fixes: b1f9d3858f72 ("ovl: use ovl_inode_lock in ovl_llseek()") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-rw-r--r--fs/overlayfs/overlayfs.h7
-rw-r--r--fs/overlayfs/util.c4
2 files changed, 8 insertions, 3 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 3623d28aa4fa..3d3f2b8bdae5 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -318,7 +318,12 @@ static inline unsigned int ovl_xino_bits(struct super_block *sb)
return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
}
-static inline int ovl_inode_lock(struct inode *inode)
+static inline void ovl_inode_lock(struct inode *inode)
+{
+ mutex_lock(&OVL_I(inode)->lock);
+}
+
+static inline int ovl_inode_lock_interruptible(struct inode *inode)
{
return mutex_lock_interruptible(&OVL_I(inode)->lock);
}
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index ea005085803f..042f7eb4f7f4 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -509,7 +509,7 @@ int ovl_copy_up_start(struct dentry *dentry, int flags)
struct inode *inode = d_inode(dentry);
int err;
- err = ovl_inode_lock(inode);
+ err = ovl_inode_lock_interruptible(inode);
if (!err && ovl_already_copied_up_locked(dentry, flags)) {
err = 1; /* Already copied up */
ovl_inode_unlock(inode);
@@ -764,7 +764,7 @@ int ovl_nlink_start(struct dentry *dentry)
return err;
}
- err = ovl_inode_lock(inode);
+ err = ovl_inode_lock_interruptible(inode);
if (err)
return err;