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authorMiklos Szeredi <mszeredi@redhat.com>2024-05-27 15:44:48 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2024-05-28 10:06:55 +0200
commitdb03d39053a97d2f2a6baec025ebdacbab5886d2 (patch)
tree96a91584e0e0655c8e6adb46dfe1e251889833bd /fs/overlayfs
parentLinux 6.10-rc1 (diff)
downloadlinux-db03d39053a97d2f2a6baec025ebdacbab5886d2.tar.xz
linux-db03d39053a97d2f2a6baec025ebdacbab5886d2.zip
ovl: fix copy-up in tmpfile
Move ovl_copy_up() call outside of ovl_want_write()/ovl_drop_write() region, since copy up may also call ovl_want_write() resulting in recursive locking on sb->s_writers. Reported-and-tested-by: syzbot+85e58cdf5b3136471d4b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000f6865106191c3e58@google.com/ Fixes: 9a87907de359 ("ovl: implement tmpfile") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/dir.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 116f542442dd..ab65e98a1def 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -1314,10 +1314,6 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
int flags = file->f_flags | OVL_OPEN_FLAGS;
int err;
- err = ovl_copy_up(dentry->d_parent);
- if (err)
- return err;
-
old_cred = ovl_override_creds(dentry->d_sb);
err = ovl_setup_cred_for_create(dentry, inode, mode, old_cred);
if (err)
@@ -1360,6 +1356,10 @@ static int ovl_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
if (!OVL_FS(dentry->d_sb)->tmpfile)
return -EOPNOTSUPP;
+ err = ovl_copy_up(dentry->d_parent);
+ if (err)
+ return err;
+
err = ovl_want_write(dentry);
if (err)
return err;