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From:   "Eric W. Biederman" <ebiederm@xmission.com>
To:     Jann Horn <jannh@google.com>
Cc:     Matthew Wilcox <willy@infradead.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Denys Vlasenko <vda.linux@googlemail.com>,
        Kees Cook <keescook@chromium.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Liam R . Howlett" <liam.howlett@oracle.com>
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Date:   Mon, 31 Jan 2022 12:46:44 -0600
In-Reply-To: <87bkzroica.fsf_-_@email.froward.int.ebiederm.org> (Eric
        W. Biederman's message of "Mon, 31 Jan 2022 12:44:53 -0600")
Message-ID: <87tudjn3or.fsf_-_@email.froward.int.ebiederm.org>
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Subject: [PATCH 3/5] coredump: Remove the WARN_ON in dump_vma_snapshot
Precedence: bulk


The condition is impossible and to the best of my knowledge has never
triggered.

We are in deep trouble if that conditions happens and we walk past
the end of our allocated array.

So delete the WARN_ON and the code that makes it look like the kernel
can handle the case of walking past the end of it's vma_meta array.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 fs/coredump.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/fs/coredump.c b/fs/coredump.c
index def2a0c9cb14..c5e7d63525c6 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -1127,10 +1127,5 @@ static bool dump_vma_snapshot(struct coredump_params *cprm)
 
 	mmap_write_unlock(mm);
 
-	if (WARN_ON(i != cprm->vma_count)) {
-		kvfree(cprm->vma_meta);
-		return false;
-	}
-
 	return true;
 }
-- 
2.29.2