diff options
| author | Christian Brauner <christian.brauner@ubuntu.com> | 2021-11-29 12:44:34 +0100 |
|---|---|---|
| committer | Dominique Martinet <asmadeus@codewreck.org> | 2022-01-10 10:00:09 +0900 |
| commit | 3cb6ee991496b67ee284c6895a0ba007e2d7bac3 (patch) | |
| tree | 339b7a7986d0977d3799b58b81efbfec8c7366ca /fs/9p | |
| parent | a7a427d1543f89ad57fda5d6b9bb70f4cecb2fba (diff) | |
9p: only copy valid iattrs in 9P2000.L setattr implementation
The 9P2000.L setattr method v9fs_vfs_setattr_dotl() copies struct iattr
values without checking whether they are valid causing unitialized
values to be copied. The 9P2000 setattr method v9fs_vfs_setattr() method
gets this right. Check whether struct iattr fields are valid first
before copying in v9fs_vfs_setattr_dotl() too and make sure that all
other fields are set to 0 apart from {g,u}id which should be set to
INVALID_{G,U}ID. This ensure that they can be safely sent over the wire
or printed for debugging later on.
Link: https://lkml.kernel.org/r/20211129114434.3637938-1-brauner@kernel.org
Link: https://lkml.kernel.org/r/000000000000a0d53f05d1c72a4c%40google.com
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: stable@kernel.org
Cc: v9fs-developer@lists.sourceforge.net
Reported-by: syzbot+dfac92a50024b54acaa4@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
[Dominique: do not set a/mtime with just ATTR_A/MTIME as discussed]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Diffstat (limited to 'fs/9p')
| -rw-r--r-- | fs/9p/vfs_inode_dotl.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 7dee89ba32e7..52f8ae79db21 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -551,7 +551,10 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns, { int retval, use_dentry = 0; struct p9_fid *fid = NULL; - struct p9_iattr_dotl p9attr; + struct p9_iattr_dotl p9attr = { + .uid = INVALID_UID, + .gid = INVALID_GID, + }; struct inode *inode = d_inode(dentry); p9_debug(P9_DEBUG_VFS, "\n"); @@ -561,14 +564,22 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns, return retval; p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid); - p9attr.mode = iattr->ia_mode; - p9attr.uid = iattr->ia_uid; - p9attr.gid = iattr->ia_gid; - p9attr.size = iattr->ia_size; - p9attr.atime_sec = iattr->ia_atime.tv_sec; - p9attr.atime_nsec = iattr->ia_atime.tv_nsec; - p9attr.mtime_sec = iattr->ia_mtime.tv_sec; - p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec; + if (iattr->ia_valid & ATTR_MODE) + p9attr.mode = iattr->ia_mode; + if (iattr->ia_valid & ATTR_UID) + p9attr.uid = iattr->ia_uid; + if (iattr->ia_valid & ATTR_GID) + p9attr.gid = iattr->ia_gid; + if (iattr->ia_valid & ATTR_SIZE) + p9attr.size = iattr->ia_size; + if (iattr->ia_valid & ATTR_ATIME_SET) { + p9attr.atime_sec = iattr->ia_atime.tv_sec; + p9attr.atime_nsec = iattr->ia_atime.tv_nsec; + } + if (iattr->ia_valid & ATTR_MTIME_SET) { + p9attr.mtime_sec = iattr->ia_mtime.tv_sec; + p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec; + } if (iattr->ia_valid & ATTR_FILE) { fid = iattr->ia_file->private_data; |