This is a note to let you know that I've just added the patch titled
fs: move should_remove_suid()
to the 5.15-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:
fs-move-should_remove_suid.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 848d854458122c791de5912b9de0f621badb04bb
Author: Christian Brauner <brauner@xxxxxxxxxx>
Date: Tue Mar 7 10:59:19 2023 -0800
fs: move should_remove_suid()
commit e243e3f94c804ecca9a8241b5babe28f35258ef4 upstream.
Move the helper from inode.c to attr.c. This keeps the the core of the
set{g,u}id stripping logic in one place when we add follow-up changes.
It is the better place anyway, since should_remove_suid() returns
ATTR_KILL_S{G,U}ID flags.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Tested-by: Leah Rumancik <leah.rumancik@xxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/attr.c b/fs/attr.c
index 686840aa91c8b..f045431bab1ad 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -20,6 +20,35 @@
#include "internal.h"
+/*
+ * The logic we want is
+ *
+ * if suid or (sgid and xgrp)
+ * remove privs
+ */
+int should_remove_suid(struct dentry *dentry)
+{
+ umode_t mode = d_inode(dentry)->i_mode;
+ int kill = 0;
+
+ /* suid always must be killed */
+ if (unlikely(mode & S_ISUID))
+ kill = ATTR_KILL_SUID;
+
+ /*
+ * sgid without any exec bits is just a mandatory locking mark; leave
+ * it alone. If some exec bits are set, it's a real sgid; kill it.
+ */
+ if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
+ kill |= ATTR_KILL_SGID;
+
+ if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
+ return kill;
+
+ return 0;
+}
+EXPORT_SYMBOL(should_remove_suid);
+
/**
* chown_ok - verify permissions to chown inode
* @mnt_userns: user namespace of the mount @inode was found from
diff --git a/fs/inode.c b/fs/inode.c
index a71fb82279bb1..3811269259e11 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1864,35 +1864,6 @@ void touch_atime(const struct path *path)
}
EXPORT_SYMBOL(touch_atime);
-/*
- * The logic we want is
- *
- * if suid or (sgid and xgrp)
- * remove privs
- */
-int should_remove_suid(struct dentry *dentry)
-{
- umode_t mode = d_inode(dentry)->i_mode;
- int kill = 0;
-
- /* suid always must be killed */
- if (unlikely(mode & S_ISUID))
- kill = ATTR_KILL_SUID;
-
- /*
- * sgid without any exec bits is just a mandatory locking mark; leave
- * it alone. If some exec bits are set, it's a real sgid; kill it.
- */
- if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
- kill |= ATTR_KILL_SGID;
-
- if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
- return kill;
-
- return 0;
-}
-EXPORT_SYMBOL(should_remove_suid);
-
/*
* Return mask of changes for notify_change() that need to be done as a
* response to write or truncate. Return 0 if nothing has to be changed.
