This is a note to let you know that I've just added the patch titled
xfs: use consistent uid/gid when grabbing dquots for inodes
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-use-consistent-uid-gid-when-grabbing-dquots-for-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 581161cea38d19639b81dfb44450d1de90cbe809
Author: Darrick J. Wong <djwong@xxxxxxxxxx>
Date: Wed Dec 18 11:17:11 2024 -0800
xfs: use consistent uid/gid when grabbing dquots for inodes
commit 24a4e1cb322e2bf0f3a1afd1978b610a23aa8f36 upstream.
I noticed that callers of xfs_qm_vop_dqalloc use the following code to
compute the anticipated uid of the new file:
mapped_fsuid(idmap, &init_user_ns);
whereas the VFS uses a slightly different computation for actually
assigning i_uid:
mapped_fsuid(idmap, i_user_ns(inode));
Technically, these are not the same things. According to Christian
Brauner, the only time that inode->i_sb->s_user_ns != &init_user_ns is
when the filesystem was mounted in a new mount namespace by an
unpriviledged user. XFS does not allow this, which is why we've never
seen bug reports about quotas being incorrect or the uid checks in
xfs_qm_vop_create_dqattach tripping debug assertions.
However, this /is/ a logic bomb, so let's make the code consistent.
Link: https://lore.kernel.org/linux-fsdevel/20240617-weitblick-gefertigt-4a41f37119fa@brauner/
Fixes: c14329d39f2d ("fs: port fs{g,u}id helpers to mnt_idmap")
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Catherine Hoang <catherine.hoang@xxxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7aa73855fab6..1e50cc9a29db 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -982,10 +982,12 @@ xfs_create(
prid = xfs_get_initial_prid(dp);
/*
- * Make sure that we have allocated dquot(s) on disk.
+ * Make sure that we have allocated dquot(s) on disk. The uid/gid
+ * computation code must match what the VFS uses to assign i_[ug]id.
+ * INHERIT adjusts the gid computation for setgid/grpid systems.
*/
- error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
- mapped_fsgid(idmap, &init_user_ns), prid,
+ error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, i_user_ns(VFS_I(dp))),
+ mapped_fsgid(idmap, i_user_ns(VFS_I(dp))), prid,
XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
&udqp, &gdqp, &pdqp);
if (error)
@@ -1131,10 +1133,12 @@ xfs_create_tmpfile(
prid = xfs_get_initial_prid(dp);
/*
- * Make sure that we have allocated dquot(s) on disk.
+ * Make sure that we have allocated dquot(s) on disk. The uid/gid
+ * computation code must match what the VFS uses to assign i_[ug]id.
+ * INHERIT adjusts the gid computation for setgid/grpid systems.
*/
- error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
- mapped_fsgid(idmap, &init_user_ns), prid,
+ error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, i_user_ns(VFS_I(dp))),
+ mapped_fsgid(idmap, i_user_ns(VFS_I(dp))), prid,
XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
&udqp, &gdqp, &pdqp);
if (error)
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 85e433df6a3f..b08be64dd10b 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -191,10 +191,12 @@ xfs_symlink(
prid = xfs_get_initial_prid(dp);
/*
- * Make sure that we have allocated dquot(s) on disk.
+ * Make sure that we have allocated dquot(s) on disk. The uid/gid
+ * computation code must match what the VFS uses to assign i_[ug]id.
+ * INHERIT adjusts the gid computation for setgid/grpid systems.
*/
- error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, &init_user_ns),
- mapped_fsgid(idmap, &init_user_ns), prid,
+ error = xfs_qm_vop_dqalloc(dp, mapped_fsuid(idmap, i_user_ns(VFS_I(dp))),
+ mapped_fsgid(idmap, i_user_ns(VFS_I(dp))), prid,
XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
&udqp, &gdqp, &pdqp);
if (error)
