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authorChristian Brauner <christian.brauner@ubuntu.com>2021-11-29 14:44:34 +0300
committerDominique Martinet <asmadeus@codewreck.org>2022-01-10 04:00:09 +0300
commit3cb6ee991496b67ee284c6895a0ba007e2d7bac3 (patch)
tree339b7a7986d0977d3799b58b81efbfec8c7366ca /fs/9p
parenta7a427d1543f89ad57fda5d6b9bb70f4cecb2fba (diff)
downloadlinux-3cb6ee991496b67ee284c6895a0ba007e2d7bac3.tar.xz
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.c29
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;