From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3F3AA3212 for ; Tue, 7 Feb 2023 13:03:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 903D1C433EF; Tue, 7 Feb 2023 13:03:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675775022; bh=2eJvU72bguGWNcOSPX5RnYvIcsZFnsi3YJtrC2eEK7I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PanLKIfUPSBlmndoRxGriylB++ipG3EaaRdDpLKjJqupD0MsHS6zv5l9ITDGDvtCk 2Ft83WuIYVAui7AO8IZqv8nn2zMdpQY7eGydGs0waCA9q2bSrVypnZr4xtjW/bt8RH Ut2JLQLJCutuBnlXegnYk32Afd5vlTR7EgXhjLtM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandre Pereira , Coly Li , Kent Overstreet , linux-bcache@vger.kernel.org, Kees Cook , Sasha Levin Subject: [PATCH 6.1 110/208] bcache: Silence memcpy() run-time false positive warnings Date: Tue, 7 Feb 2023 13:56:04 +0100 Message-Id: <20230207125639.351394298@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230207125634.292109991@linuxfoundation.org> References: <20230207125634.292109991@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Kees Cook [ Upstream commit be0d8f48ad97f5b775b0af3310343f676dbf318a ] struct bkey has internal padding in a union, but it isn't always named the same (e.g. key ## _pad, key_p, etc). This makes it extremely hard for the compiler to reason about the available size of copies done against such keys. Use unsafe_memcpy() for now, to silence the many run-time false positive warnings: memcpy: detected field-spanning write (size 264) of single field "&i->j" at drivers/md/bcache/journal.c:152 (size 240) memcpy: detected field-spanning write (size 24) of single field "&b->key" at drivers/md/bcache/btree.c:939 (size 16) memcpy: detected field-spanning write (size 24) of single field "&temp.key" at drivers/md/bcache/extents.c:428 (size 16) Reported-by: Alexandre Pereira Link: https://bugzilla.kernel.org/show_bug.cgi?id=216785 Acked-by: Coly Li Cc: Kent Overstreet Cc: linux-bcache@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230106060229.never.047-kees@kernel.org Signed-off-by: Sasha Levin --- drivers/md/bcache/bcache_ondisk.h | 3 ++- drivers/md/bcache/journal.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/bcache_ondisk.h b/drivers/md/bcache/bcache_ondisk.h index 97413586195b..f96034e0ba4f 100644 --- a/drivers/md/bcache/bcache_ondisk.h +++ b/drivers/md/bcache/bcache_ondisk.h @@ -106,7 +106,8 @@ static inline unsigned long bkey_bytes(const struct bkey *k) return bkey_u64s(k) * sizeof(__u64); } -#define bkey_copy(_dest, _src) memcpy(_dest, _src, bkey_bytes(_src)) +#define bkey_copy(_dest, _src) unsafe_memcpy(_dest, _src, bkey_bytes(_src), \ + /* bkey is always padded */) static inline void bkey_copy_key(struct bkey *dest, const struct bkey *src) { diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c index e5da469a4235..c182c21de2e8 100644 --- a/drivers/md/bcache/journal.c +++ b/drivers/md/bcache/journal.c @@ -149,7 +149,8 @@ reread: left = ca->sb.bucket_size - offset; bytes, GFP_KERNEL); if (!i) return -ENOMEM; - memcpy(&i->j, j, bytes); + unsafe_memcpy(&i->j, j, bytes, + /* "bytes" was calculated by set_bytes() above */); /* Add to the location after 'where' points to */ list_add(&i->list, where); ret = 1; -- 2.39.0