Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757754AbaDVUUy (ORCPT ); Tue, 22 Apr 2014 16:20:54 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36343 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756475AbaDVUUv (ORCPT ); Tue, 22 Apr 2014 16:20:51 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Dan Carpenter , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.8 022/133] isdnloop: several buffer overflows Date: Tue, 22 Apr 2014 13:12:40 -0700 Message-Id: <1398197671-12786-23-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398197671-12786-1-git-send-email-kamal@canonical.com> References: <1398197671-12786-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.22 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter [ Upstream commit 7563487cbf865284dcd35e9ef5a95380da046737 ] There are three buffer overflows addressed in this patch. 1) In isdnloop_fake_err() we add an 'E' to a 60 character string and then copy it into a 60 character buffer. I have made the destination buffer 64 characters and I'm changed the sprintf() to a snprintf(). 2) In isdnloop_parse_cmd(), p points to a 6 characters into a 60 character buffer so we have 54 characters. The ->eazlist[] is 11 characters long. I have modified the code to return if the source buffer is too long. 3) In isdnloop_command() the cbuf[] array was 60 characters long but the max length of the string then can be up to 79 characters. I made the cbuf array 80 characters long and changed the sprintf() to snprintf(). I also removed the temporary "dial" buffer and changed it to use "p" directly. Unfortunately, we pass the "cbuf" string from isdnloop_command() to isdnloop_writecmd() which truncates anything over 60 characters to make it fit in card->omsg[]. (It can accept values up to 255 characters so long as there is a '\n' character every 60 characters). For now I have just fixed the memory corruption bug and left the other problems in this driver alone. Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/isdn/isdnloop/isdnloop.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c index e1f8748..5a4da94 100644 --- a/drivers/isdn/isdnloop/isdnloop.c +++ b/drivers/isdn/isdnloop/isdnloop.c @@ -518,9 +518,9 @@ static isdnloop_stat isdnloop_cmd_table[] = static void isdnloop_fake_err(isdnloop_card *card) { - char buf[60]; + char buf[64]; - sprintf(buf, "E%s", card->omsg); + snprintf(buf, sizeof(buf), "E%s", card->omsg); isdnloop_fake(card, buf, -1); isdnloop_fake(card, "NAK", -1); } @@ -903,6 +903,8 @@ isdnloop_parse_cmd(isdnloop_card *card) case 7: /* 0x;EAZ */ p += 3; + if (strlen(p) >= sizeof(card->eazlist[0])) + break; strcpy(card->eazlist[ch - 1], p); break; case 8: @@ -1133,7 +1135,7 @@ isdnloop_command(isdn_ctrl *c, isdnloop_card *card) { ulong a; int i; - char cbuf[60]; + char cbuf[80]; isdn_ctrl cmd; isdnloop_cdef cdef; @@ -1198,7 +1200,6 @@ isdnloop_command(isdn_ctrl *c, isdnloop_card *card) break; if ((c->arg & 255) < ISDNLOOP_BCH) { char *p; - char dial[50]; char dcode[4]; a = c->arg; @@ -1210,10 +1211,10 @@ isdnloop_command(isdn_ctrl *c, isdnloop_card *card) } else /* Normal Dial */ strcpy(dcode, "CAL"); - strcpy(dial, p); - sprintf(cbuf, "%02d;D%s_R%s,%02d,%02d,%s\n", (int) (a + 1), - dcode, dial, c->parm.setup.si1, - c->parm.setup.si2, c->parm.setup.eazmsn); + snprintf(cbuf, sizeof(cbuf), + "%02d;D%s_R%s,%02d,%02d,%s\n", (int) (a + 1), + dcode, p, c->parm.setup.si1, + c->parm.setup.si2, c->parm.setup.eazmsn); i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card); } break; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/