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| author | Alexey Gladkov <legion@kernel.org> | 2021-04-22 14:27:16 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-04-30 14:14:03 -0500 |
| commit | c1ada3dc7219b02b3467aa906c2f5f8b098578d1 (patch) | |
| tree | ed42c25748ccbec5d4704b99d4934f1b6c91ffe8 /kernel/user_namespace.c | |
| parent | e4aebf06695c32d49f1007f9d252f97b5b2998a7 (diff) | |
| download | linux-c1ada3dc7219b02b3467aa906c2f5f8b098578d1.tar.gz linux-c1ada3dc7219b02b3467aa906c2f5f8b098578d1.tar.bz2 linux-c1ada3dc7219b02b3467aa906c2f5f8b098578d1.zip | |
ucounts: Set ucount_max to the largest positive value the type can hold
The ns->ucount_max[] is signed long which is less than the rlimit size.
We have to protect ucount_max[] from overflow and only use the largest
value that we can hold.
On 32bit using "long" instead of "unsigned long" to hold the counts has
the downside that RLIMIT_MSGQUEUE and RLIMIT_MEMLOCK are limited to 2GiB
instead of 4GiB. I don't think anyone cares but it should be mentioned
in case someone does.
The RLIMIT_NPROC and RLIMIT_SIGPENDING used atomic_t so their maximum
hasn't changed.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/1825a5dfa18bc5a570e79feb05e2bd07fd57e7e3.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | kernel/user_namespace.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 892da1360862..d4a545bbab7f 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -122,10 +122,10 @@ int create_user_ns(struct cred *new) for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) { ns->ucount_max[i] = INT_MAX; } - ns->ucount_max[UCOUNT_RLIMIT_NPROC] = rlimit(RLIMIT_NPROC); - ns->ucount_max[UCOUNT_RLIMIT_MSGQUEUE] = rlimit(RLIMIT_MSGQUEUE); - ns->ucount_max[UCOUNT_RLIMIT_SIGPENDING] = rlimit(RLIMIT_SIGPENDING); - ns->ucount_max[UCOUNT_RLIMIT_MEMLOCK] = rlimit(RLIMIT_MEMLOCK); + set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)); + set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MSGQUEUE, rlimit(RLIMIT_MSGQUEUE)); + set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_SIGPENDING, rlimit(RLIMIT_SIGPENDING)); + set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MEMLOCK, rlimit(RLIMIT_MEMLOCK)); ns->ucounts = ucounts; /* Inherit USERNS_SETGROUPS_ALLOWED from our parent */ |