diff options
| author | Alexey Gladkov <legion@kernel.org> | 2021-04-22 14:27:09 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-04-30 14:14:00 -0500 |
| commit | 905ae01c4ae2ae3df05bb141801b1db4b7d83c61 (patch) | |
| tree | c4216c817bd6859c8028a25900bcfe4330c1e3c9 /include/linux/user_namespace.h | |
| parent | f9c82a4ea89c384d49ce03768ba88d049ed3f1f0 (diff) | |
Add a reference to ucounts for each cred
For RLIMIT_NPROC and some other rlimits the user_struct that holds the
global limit is kept alive for the lifetime of a process by keeping it
in struct cred. Adding a pointer to ucounts in the struct cred will
allow to track RLIMIT_NPROC not only for user in the system, but for
user in the user_namespace.
Updating ucounts may require memory allocation which may fail. So, we
cannot change cred.ucounts in the commit_creds() because this function
cannot fail and it should always return 0. For this reason, we modify
cred.ucounts before calling the commit_creds().
Changelog
v6:
* Fix null-ptr-deref in is_ucounts_overlimit() detected by trinity. This
error was caused by the fact that cred_alloc_blank() left the ucounts
pointer empty.
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/b37aaef28d8b9b0d757e07ba6dd27281bbe39259.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'include/linux/user_namespace.h')
| -rw-r--r-- | include/linux/user_namespace.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index c242c10906c5..7919b80d57ed 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -100,11 +100,15 @@ struct ucounts { }; extern struct user_namespace init_user_ns; +extern struct ucounts init_ucounts; bool setup_userns_sysctls(struct user_namespace *ns); void retire_userns_sysctls(struct user_namespace *ns); struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); void dec_ucount(struct ucounts *ucounts, enum ucount_type type); +struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid); +struct ucounts *get_ucounts(struct ucounts *ucounts); +void put_ucounts(struct ucounts *ucounts); #ifdef CONFIG_USER_NS |