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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-16 20:51:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-23 14:03:20 +0300 |
| commit | f418bfabea43325f306276226f64ebc7de1b7d56 (patch) | |
| tree | 994464193a4e1cf79511dbc39cf9bbc66bf01871 /kernel | |
| parent | d464492eb3917e8a1be67c5aa6a4ad8fe7551652 (diff) | |
| download | linux-f418bfabea43325f306276226f64ebc7de1b7d56.tar.xz | |
ucounts: In set_cred_ucounts assume new->ucounts is non-NULL
commit 99c31f9feda41d0f10d030dc04ba106c93295aa2 upstream.
Any cred that is destined for use by commit_creds must have a non-NULL
cred->ucounts field. Only curing credential construction is a NULL
cred->ucounts valid. Only abort_creds, put_cred, and put_cred_rcu
needs to deal with a cred with a NULL ucount. As set_cred_ucounts is
non of those case don't confuse people by handling something that can
not happen.
Link: https://lkml.kernel.org/r/871r4irzds.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cred.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/cred.c b/kernel/cred.c index 1ae0b4948a5a..473d17c431f3 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -676,15 +676,14 @@ int set_cred_ucounts(struct cred *new) * This optimization is needed because alloc_ucounts() uses locks * for table lookups. */ - if (old_ucounts && old_ucounts->ns == new->user_ns && uid_eq(old_ucounts->uid, new->euid)) + if (old_ucounts->ns == new->user_ns && uid_eq(old_ucounts->uid, new->euid)) return 0; if (!(new_ucounts = alloc_ucounts(new->user_ns, new->euid))) return -EAGAIN; new->ucounts = new_ucounts; - if (old_ucounts) - put_ucounts(old_ucounts); + put_ucounts(old_ucounts); return 0; } |