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| author | Christian Brauner <christian.brauner@ubuntu.com> | 2022-06-28 14:16:11 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-02 16:41:15 +0200 |
| commit | 3374eb1b0afc9d4b2c35599d240b062488d976b4 (patch) | |
| tree | 71525b6578fefa76f2d4139b2c2b0705da63a2dd | |
| parent | 7bc23abcb4142ea3cb81d1772b8c6501bd63f2ad (diff) | |
| download | linux-3374eb1b0afc9d4b2c35599d240b062488d976b4.tar.gz linux-3374eb1b0afc9d4b2c35599d240b062488d976b4.tar.bz2 linux-3374eb1b0afc9d4b2c35599d240b062488d976b4.zip | |
fs: tweak fsuidgid_has_mapping()
commit 476860b3eb4a50958243158861d5340066df5af2 upstream.
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)
Link: https://lore.kernel.org/r/20211130121032.3753852-4-brauner@kernel.org (v2)
Link: https://lore.kernel.org/r/20211203111707.3901969-4-brauner@kernel.org
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>
Reviewed-by: Seth Forshee <sforshee@digitalocean.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/fs.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index b1d446d71c3f..ffc06557618c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1697,10 +1697,18 @@ 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); |