From a4859d75944a726533ab86d24bb5ffd1b2b7d6cc Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 29 Jun 2016 08:26:59 +0200 Subject: ovl: fix dentry leak for default_permissions When using the 'default_permissions' mount option, ovl_permission() on non-directories was missing a dput(alias), resulting in "BUG Dentry still in use". Signed-off-by: Miklos Szeredi Fixes: 8d3095f4ad47 ("ovl: default permissions") Cc: # v4.5+ --- fs/overlayfs/inode.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/overlayfs/inode.c') diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 1dbeab6cf96e..8514d692042b 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -121,16 +121,18 @@ int ovl_permission(struct inode *inode, int mask) err = vfs_getattr(&realpath, &stat); if (err) - return err; + goto out_dput; + err = -ESTALE; if ((stat.mode ^ inode->i_mode) & S_IFMT) - return -ESTALE; + goto out_dput; inode->i_mode = stat.mode; inode->i_uid = stat.uid; inode->i_gid = stat.gid; - return generic_permission(inode, mask); + err = generic_permission(inode, mask); + goto out_dput; } /* Careful in RCU walk mode */ -- cgit v1.2.3-70-g09d2 From 03bea60409328de54e4ff7ec41672e12a9cb0908 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 29 Jun 2016 16:03:55 +0200 Subject: ovl: get_write_access() in truncate When truncating a file we should check write access on the underlying inode. And we should do so on the lower file as well (before copy-up) for consistency. Original patch and test case by Aihua Zhang. - - >o >o - - test.c - - >o >o - - #include #include #include int main(int argc, char *argv[]) { int ret; ret = truncate(argv[0], 4096); if (ret != -1) { fprintf(stderr, "truncate(argv[0]) should have failed\n"); return 1; } if (errno != ETXTBSY) { perror("truncate(argv[0])"); return 1; } return 0; } - - >o >o - - >o >o - - >o >o - - Reported-by: Aihua Zhang Signed-off-by: Miklos Szeredi Cc: --- fs/overlayfs/inode.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'fs/overlayfs/inode.c') diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 8514d692042b..c831c2e5f803 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -59,16 +59,37 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr) if (err) goto out; + if (attr->ia_valid & ATTR_SIZE) { + struct inode *realinode = d_inode(ovl_dentry_real(dentry)); + + err = -ETXTBSY; + if (atomic_read(&realinode->i_writecount) < 0) + goto out_drop_write; + } + err = ovl_copy_up(dentry); if (!err) { + struct inode *winode = NULL; + upperdentry = ovl_dentry_upper(dentry); + if (attr->ia_valid & ATTR_SIZE) { + winode = d_inode(upperdentry); + err = get_write_access(winode); + if (err) + goto out_drop_write; + } + inode_lock(upperdentry->d_inode); err = notify_change(upperdentry, attr, NULL); if (!err) ovl_copyattr(upperdentry->d_inode, dentry->d_inode); inode_unlock(upperdentry->d_inode); + + if (winode) + put_write_access(winode); } +out_drop_write: ovl_drop_write(dentry); out: return err; -- cgit v1.2.3-70-g09d2