tracefs: Set the group ownership in apply_options() not parse_options()

commit 851e99ebeec3f4a672bb5010cf1ece095acee447 upstream.

Al Viro brought it to my attention that the dentries may not be filled
when the parse_options() is called, causing the call to set_gid() to
possibly crash. It should only be called if parse_options() succeeds
totally anyway.

He suggested the logical place to do the update is in apply_options().

Link: https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]

Cc: [email protected]
Acked-by: Al Viro <[email protected]>
Reported-by: Al Viro <[email protected]>
Fixes: 48b27b6b5191 ("tracefs: Set all files to the same group ownership as the mount option")
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Steven Rostedt (Google) 2022-02-25 15:34:26 -05:00 • committed by Greg Kroah-Hartman
commit 40256addf5

View file

@ -262,7 +262,6 @@ static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
if (!gid_valid(gid))
return -EINVAL;
opts->gid = gid;
set_gid(tracefs_mount->mnt_root, gid);
break;
case Opt_mode:
if (match_octal(&args[0], &option))
@ -289,7 +288,9 @@ static int tracefs_apply_options(struct super_block *sb)
inode->i_mode |= opts->mode;
inode->i_uid = opts->uid;
inode->i_gid = opts->gid;
/* Set all the group ids to the mount option */
set_gid(sb->s_root, opts->gid);
return 0;
}