From patchwork Thu Jan 9 07:39:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stephen Rothwell X-Patchwork-Id: 1220186 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47tdM9223dz9sR0 for ; Thu, 9 Jan 2020 18:40:37 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=canb.auug.org.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=canb.auug.org.au header.i=@canb.auug.org.au header.a=rsa-sha256 header.s=201702 header.b=Apk3yLiO; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47tdM81lHgzDqXs for ; Thu, 9 Jan 2020 18:40:36 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 47tdKc2Z9CzDqWb for ; Thu, 9 Jan 2020 18:39:16 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=canb.auug.org.au Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=canb.auug.org.au header.i=@canb.auug.org.au header.a=rsa-sha256 header.s=201702 header.b=Apk3yLiO; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 47tdKZ2HD0z9sR0; Thu, 9 Jan 2020 18:39:14 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=canb.auug.org.au; s=201702; t=1578555554; bh=jQgCe2rWBbz1wWmLtYGxjDB1NY2hlasRFcbCGn/Bpwc=; h=Date:From:To:Cc:Subject:From; b=Apk3yLiOHhagAosAcbu/QPJFVEzyur/oJLN0AvcMjY+f3WTbyNEjatBc9k1YIuaW+ bT5ESFkNPAnOUwZxJem4rX/YL1VP7waiKQwpXyB4ZiNdlsz2JGaLSTPHIww6wfxKp+ aT8LmzqJS9r/rvDBTNSCXFaYK7KlXD+uuen6KY5vhlTnwFfZmJgA7DOR7snfkxxoO7 xWc5GazEjiIT4RtarstY3a41go4ZGuKG8iiExItsIWMr6ZgmBiE08M9/wE/S4Z90S0 OAdEWCg8lL5U4KAviqT6JavE90m52e2gamnpo/3qgDvcC2GbezBnQOEcLQXx+dcHl1 zsmHsemRtPvsA== Date: Thu, 9 Jan 2020 18:39:12 +1100 From: Stephen Rothwell To: Greg Kroah-Hartman , Jiri Slaby Subject: [PATCH] evh_bytechan: fix out of bounds accesses Message-ID: <20200109183912.5fcb52aa@canb.auug.org.au> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: PowerPC Mailing List Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" ev_byte_channel_send() assumes that its third argument is a 16 byte array. Some places where it is called it may not be (or we can't easily tell if it is). Newer compilers have started producing warnings about this, so make sure we actually pass a 16 byte array. There may be more elegant solutions to this, but the driver is quite old and hasn't been updated in many years. The warnings (from a powerpc allyesconfig build) are: In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: drivers/tty/ehv_bytechan.c: In function ‘ehv_bc_udbg_putc’: arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 298 | r6 = be32_to_cpu(p[1]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’ 298 | r6 = be32_to_cpu(p[1]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: arch/powerpc/include/asm/epapr_hcalls.h:299:20: warning: array subscript 2 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 299 | r7 = be32_to_cpu(p[2]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:299:7: note: in expansion of macro ‘be32_to_cpu’ 299 | r7 = be32_to_cpu(p[2]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: arch/powerpc/include/asm/epapr_hcalls.h:300:20: warning: array subscript 3 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 300 | r8 = be32_to_cpu(p[3]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:300:7: note: in expansion of macro ‘be32_to_cpu’ 300 | r8 = be32_to_cpu(p[3]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 298 | r6 = be32_to_cpu(p[1]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’ 298 | r6 = be32_to_cpu(p[1]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: arch/powerpc/include/asm/epapr_hcalls.h:299:20: warning: array subscript 2 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 299 | r7 = be32_to_cpu(p[2]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:299:7: note: in expansion of macro ‘be32_to_cpu’ 299 | r7 = be32_to_cpu(p[2]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: arch/powerpc/include/asm/epapr_hcalls.h:300:20: warning: array subscript 3 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 300 | r8 = be32_to_cpu(p[3]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:300:7: note: in expansion of macro ‘be32_to_cpu’ 300 | r8 = be32_to_cpu(p[3]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ Fixes: dcd83aaff1c8 ("tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver") Cc: Michael Ellerman Cc: PowerPC Mailing List Signed-off-by: Stephen Rothwell Signed-off-by: Stephen Rothwell Tested-by: Laurentiu Tudor Tested-by: Laurentiu Tudor --- drivers/tty/ehv_bytechan.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) I have only build tested this change so it would be good to get some response from the PowerPC maintainers/developers. diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c index 769e0a5d1dfc..546f80c49ae6 100644 --- a/drivers/tty/ehv_bytechan.c +++ b/drivers/tty/ehv_bytechan.c @@ -136,6 +136,20 @@ static int find_console_handle(void) return 1; } +static unsigned int local_ev_byte_channel_send(unsigned int handle, + unsigned int *count, const char *p) +{ + char buffer[EV_BYTE_CHANNEL_MAX_BYTES]; + unsigned int c = *count; + + if (c < sizeof(buffer)) { + memcpy(buffer, p, c); + memset(&buffer[c], 0, sizeof(buffer) - c); + p = buffer; + } + return ev_byte_channel_send(handle, count, p); +} + /*************************** EARLY CONSOLE DRIVER ***************************/ #ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC @@ -154,7 +168,7 @@ static void byte_channel_spin_send(const char data) do { count = 1; - ret = ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, + ret = local_ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, &count, &data); } while (ret == EV_EAGAIN); } @@ -221,7 +235,7 @@ static int ehv_bc_console_byte_channel_send(unsigned int handle, const char *s, while (count) { len = min_t(unsigned int, count, EV_BYTE_CHANNEL_MAX_BYTES); do { - ret = ev_byte_channel_send(handle, &len, s); + ret = local_ev_byte_channel_send(handle, &len, s); } while (ret == EV_EAGAIN); count -= len; s += len; @@ -401,7 +415,7 @@ static void ehv_bc_tx_dequeue(struct ehv_bc_data *bc) CIRC_CNT_TO_END(bc->head, bc->tail, BUF_SIZE), EV_BYTE_CHANNEL_MAX_BYTES); - ret = ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail); + ret = local_ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail); /* 'len' is valid only if the return code is 0 or EV_EAGAIN */ if (!ret || (ret == EV_EAGAIN))