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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-16 12:51:58 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-20 10:45:34 -0500 |
| commit | 99c31f9feda41d0f10d030dc04ba106c93295aa2 (patch) | |
| tree | cbc53b3ce9d8731a2d3b38cfe39f02c7fa9a64a3 | |
| parent | 5ebcbe342b1c12fae44b4f83cbeae1520e09857e (diff) | |
| download | linux-99c31f9feda41d0f10d030dc04ba106c93295aa2.tar.gz | |
ucounts: In set_cred_ucounts assume new->ucounts is non-NULL
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>
| -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; } |