| Message ID | 20211130121032.3753852-4-brauner@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Extend and tweak mapping support | expand |
On Tue, Nov 30, 2021 at 01:10:25PM +0100, Christian Brauner wrote: > From: Christian Brauner <christian.brauner@ubuntu.com> > > If the caller's fs{g,u}id aren't mapped in the mount's idmapping we can > return early and skip the check whether the mapped fs{g,u}id also have a > mapping in the filesystem's idmapping. If the fs{g,u}id aren't mapped in > the mount's idmapping they consequently can't be mapped in the > filesystem's idmapping. So there's no point in checking that. > > Link: https://lore.kernel.org/r/20211123114227.3124056-4-brauner@kernel.org (v1) > Cc: Seth Forshee <sforshee@digitalocean.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Al Viro <viro@zeniv.linux.org.uk> > CC: linux-fsdevel@vger.kernel.org > Reviewed-by: Amir Goldstein <amir73il@gmail.com> > Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Seth Forshee <sforshee@digitalocean.com> > --- > /* v2 */ > unchanged > --- > include/linux/fs.h | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index f5d1ae0a783a..28ab20ce0adc 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1695,10 +1695,18 @@ static inline void inode_fsgid_set(struct inode *inode, > static inline bool fsuidgid_has_mapping(struct super_block *sb, > struct user_namespace *mnt_userns) > { > - struct user_namespace *s_user_ns = sb->s_user_ns; > + struct user_namespace *fs_userns = sb->s_user_ns; > + kuid_t kuid; > + kgid_t kgid; > > - return kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) && > - kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns)); > + kuid = mapped_fsuid(mnt_userns); > + if (!uid_valid(kuid)) > + return false; > + kgid = mapped_fsgid(mnt_userns); > + if (!gid_valid(kgid)) > + return false; > + return kuid_has_mapping(fs_userns, kuid) && > + kgid_has_mapping(fs_userns, kgid); > } > > extern struct timespec64 current_time(struct inode *inode); > -- > 2.30.2 >
diff --git a/include/linux/fs.h b/include/linux/fs.h index f5d1ae0a783a..28ab20ce0adc 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1695,10 +1695,18 @@ static inline void inode_fsgid_set(struct inode *inode, static inline bool fsuidgid_has_mapping(struct super_block *sb, struct user_namespace *mnt_userns) { - struct user_namespace *s_user_ns = sb->s_user_ns; + struct user_namespace *fs_userns = sb->s_user_ns; + kuid_t kuid; + kgid_t kgid; - return kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) && - kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns)); + kuid = mapped_fsuid(mnt_userns); + if (!uid_valid(kuid)) + return false; + kgid = mapped_fsgid(mnt_userns); + if (!gid_valid(kgid)) + return false; + return kuid_has_mapping(fs_userns, kuid) && + kgid_has_mapping(fs_userns, kgid); } extern struct timespec64 current_time(struct inode *inode);