From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 19 Feb 2025 17:49:33 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tknGQ-004Nnv-1M for lore@lore.pengutronix.de; Wed, 19 Feb 2025 17:49:33 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tknGP-0005os-1X for lore@pengutronix.de; Wed, 19 Feb 2025 17:49:33 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PE8wDczk35FJ/6sRtOqAvcDdLTw9/10tAUryW45baU0=; b=Uk0gSS/Lk3eGQaPvtbB8IWgcSX qaSDFLkKUsmsfbZy+LbcoqDBh5JKBNW8rF982RkB0z/wJb5Bi3smMZkAVgtlJtwV5hbaExswsVang 5ddQ+nkZvzIh1Z7AqFio/1xDd1HbK5l2VXirH5p2kdvvIJupQgUflcfd8nXofQHKtCXrdiWy0PYET dwHAptrp92jTRzR+svSiXpc9n8ZtiVV96TJI9peHwpsoze5V3azssMmqviKo6rSCSKqzcOxJj0F5c YHIWtKHwjSVmQnpRMMOufoHCbfM4sro1lwbjpJuKpTo9Evm7ju7ILAV5p18aNdVGyqjuNbpsCMa9J 8qYzyOmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tknG1-0000000Dvb5-3TaW; Wed, 19 Feb 2025 16:49:09 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tknFy-0000000DvYa-41ud for barebox@lists.infradead.org; Wed, 19 Feb 2025 16:49:08 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1tknFx-0005dz-PH; Wed, 19 Feb 2025 17:49:05 +0100 Message-ID: <61270515-e726-4447-b924-b9c1f919cf74@pengutronix.de> Date: Wed, 19 Feb 2025 17:49:05 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Sascha Hauer , Barebox List Cc: Jonathan Bar Or References: <20250219141844.1912413-1-s.hauer@pengutronix.de> <20250219141844.1912413-2-s.hauer@pengutronix.de> Content-Language: en-US From: Ahmad Fatoum In-Reply-To: <20250219141844.1912413-2-s.hauer@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250219_084907_015645_5ED2EA0F X-CRM114-Status: GOOD ( 24.36 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.4 required=4.0 tests=AWL,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 1/5] CVE-2025-26722: fs: squashfs: Ensure positive inode length X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) On 19.02.25 15:18, Sascha Hauer wrote: > In squashfs_get_link() we have: > > int length = min_t(int, i_size_read(inode), PAGE_SIZE); > > The inode size is a 64bit number directly read from the device which > is interpreted as a 32bit signed number above. An inode size with the > lower 32bits set to 0xffffffff results in length being -1. Later we > do a: > > symlink = malloc(length + 1); > > With length being -1 this results in allocating a zero size buffer which > is then overwritten by following code. > > Fix this by first making sure that the inode length is positive. > Afterwards limit the length to the desired range, explicitly using > loff_t as the type to compare to make sure we do not truncate the > original data type during comparison. > > Reported-by: Jonathan Bar Or > Signed-off-by: Sascha Hauer Reviewed-by: Ahmad Fatoum > --- > fs/squashfs/symlink.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c > index 40b9bdcc8b..cb14eb20a5 100644 > --- a/fs/squashfs/symlink.c > +++ b/fs/squashfs/symlink.c > @@ -43,16 +43,20 @@ > static const char *squashfs_get_link(struct dentry *dentry, struct inode *inode) > { > struct super_block *sb = inode->i_sb; > - int index = 0; > u64 block = squashfs_i(inode)->start; > int offset = squashfs_i(inode)->offset; > - int length = min_t(int, i_size_read(inode) - index, PAGE_SIZE); > + size_t length; > int bytes; > unsigned char *symlink; > > TRACE("Entered squashfs_symlink_readpage, start block " > "%llx, offset %x\n", block, offset); > > + if (i_size_read(inode) < 0) > + return NULL; > + > + length = min_t(loff_t, i_size_read(inode), PAGE_SIZE); > + > symlink = malloc(length + 1); > if (!symlink) > return NULL; -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |