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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-16 12:47:51 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-19 11:04:25 -0500 |
| commit | 34dc2fd6e6908499b669c7b45320cddf38b332e1 (patch) | |
| tree | 5674fdd26d21efd860afc4c571c250cfa511aed0 /kernel/cred.c | |
| parent | 629715adc62b0ad27ab04d0aa73a71927f886910 (diff) | |
| download | lwn-34dc2fd6e6908499b669c7b45320cddf38b332e1.tar.gz lwn-34dc2fd6e6908499b669c7b45320cddf38b332e1.zip | |
ucounts: Proper error handling in set_cred_ucounts
Instead of leaking the ucounts in new if alloc_ucounts fails, store
the result of alloc_ucounts into a temporary variable, which is later
assigned to new->ucounts.
Cc: stable@vger.kernel.org
Fixes: 905ae01c4ae2 ("Add a reference to ucounts for each cred")
Link: https://lkml.kernel.org/r/87pms2s0v8.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>
Diffstat (limited to 'kernel/cred.c')
| -rw-r--r-- | kernel/cred.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/cred.c b/kernel/cred.c index 3d163bfd64a9..16c05dfbec4d 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -669,7 +669,7 @@ int set_cred_ucounts(struct cred *new) { struct task_struct *task = current; const struct cred *old = task->real_cred; - struct ucounts *old_ucounts = new->ucounts; + struct ucounts *new_ucounts, *old_ucounts = new->ucounts; if (new->user == old->user && new->user_ns == old->user_ns) return 0; @@ -681,9 +681,10 @@ int set_cred_ucounts(struct cred *new) if (old_ucounts && 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))) + if (!(new_ucounts = alloc_ucounts(new->user_ns, new->euid))) return -EAGAIN; + new->ucounts = new_ucounts; if (old_ucounts) put_ucounts(old_ucounts); |