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authorEric W. Biederman <ebiederm@xmission.com>2022-02-09 18:09:41 -0600
committerEric W. Biederman <ebiederm@xmission.com>2022-02-17 09:11:57 -0600
commit0cbae9e24fa7d6c6e9f828562f084da82217a0c5 (patch)
treed00fdbcb46cfce60dfe064db7b6a8dc2568da262 /kernel/ucount.c
parentc923a8e7edb010da67424077cbf1a6f1396ebd2e (diff)
downloadlinux-0cbae9e24fa7d6c6e9f828562f084da82217a0c5.tar.gz
ucounts: Handle wrapping in is_ucounts_overlimit
While examining is_ucounts_overlimit and reading the various messages
I realized that is_ucounts_overlimit fails to deal with counts that
may have wrapped.

Being wrapped should be a transitory state for counts and they should
never be wrapped for long, but it can happen so handle it.

Cc: stable@vger.kernel.org
Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts")
Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/ucount.c')
-rw-r--r--kernel/ucount.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 65b597431c86..06ea04d44685 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -350,7 +350,8 @@ bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsign
 	if (rlimit > LONG_MAX)
 		max = LONG_MAX;
 	for (iter = ucounts; iter; iter = iter->ns->ucounts) {
-		if (get_ucounts_value(iter, type) > max)
+		long val = get_ucounts_value(iter, type);
+		if (val < 0 || val > max)
 			return true;
 		max = READ_ONCE(iter->ns->ucount_max[type]);
 	}