From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794063883; b=MUcfgdFB/cWYuMgFnhQ62pRHoWUgmMklWSgqxU+23ae6bO5kVxGcQ/7orGitoqQmBNKs tGGMjvy+J/PW56n53eYXFH5hL9jFp2jCFFZTjn+fg3b9GVN6Gvu7qvEfdQA9AFnx7MFnH IMrIxtB5KMIBEDjYuDO4pHGQV2XvpVT8Av6ryyoNEDSCIQ8ilT4Dkvl04WIf+FGH5cvuS sxLR2sTbSZR5mf20I/mC4qeCMjw1lHKUleEtfyyXQUxqm+7vuk1Qc4F9OzRCpDlF9E0Ie 9iKxTD4XWa/Q2LhFT3HlRmNxnU7TX4pAL9gNLpCRosCzCTo6oZs6gCZsYHSaknYUFUQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063883; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=O0iF6N0zmK6MWZoRMRFtehbkHe1yiYJA+nZQ1AKP4Tk=; b=BmiI73TC1EpR8xZKAtIpwkbvd46gbavWdM5+m9aJSMKViwzOYRFLm9b5jF+ld5NpQX0U GU9yFTn9D6KJXk0/KzwX33Pp5hfw17pDZz/RkoQ1Le5uM87trDrI3moprvR3BmETzPBYy s2uJehJtDSSZ9hu9k5K2Qq8gZN0IzGpx/A4qsDFBu1+fPC4olenW1o00xjDORcsNybil1 CDyneka3L40PReSlu+hil3WVSu6pNNH3XgQhkwU1C8G4YIpbYqxWQxoKIxxFOA+qIk3xU kbS3CyaGy4FpXXjC4c1DPJv2KFIxQw6wsNn1j0olrycuor58DEUkpK1NcMNgCar/1vg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=sEkNVHaC; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D03F7606A32F; Sat, 7 Nov 2026 15:04:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=sEkNVHaC Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85B771F008A1; Sat, 7 Nov 2026 15:04:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063882; bh=O0iF6N0zmK6MWZoRMRFtehbkHe1yiYJA+nZQ1AKP4Tk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sEkNVHaCxWPYBlPt/n6UB/cn1g9oDZr0muN6ho8GOthI819xJN20lbI77jt+Vk6/s PoC4E9Jp261HNhM36i2Q0tgR9Kng95V+AwClQnyi80+Zzrt58S4bMC7ttf8joSYURK lOdhudHJUmL5nUnCE780gqiVyGgF0XkkR6G3RusM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yunpeng Tian , Gongming Wang , Mingda Zhang , Qinrun Dai , Jan Kara , Sasha Levin Subject: [PATCH 7.3 0048/1257] udf: validate the device specification EA before using it Date: Sat, 7 Nov 2026 08:39:04 -0500 Message-ID: <20261107134940.738362978@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yunpeng Tian [ Upstream commit 9a2390959685ac35a58c80c8016120849a2babf6 ] udf_get_extendedattr() bounds an extended attribute only against struct genericFormat, which is 12 bytes. A type-12 device specification is struct deviceSpec, which is 24 bytes plus a flexible impUse array. Thus a corrupted filesystem can contain extended attribute that is accepted by udf_get_extendedattr() but udf_write_inode() or udf_read_inode() may access beyond the end of provided buffer. Provide a udf_device_spec_valid() check to validate correctness of extended attribute that is a deviceSpec. While here, check the result of udf_add_extendedattr() before dereferencing it as it can return NULL in case of error. [JK: Removed duplicated validity checks] Reported-by: Yunpeng Tian Reported-by: Gongming Wang Reported-by: Mingda Zhang Reported-by: Qinrun Dai Cc: stable@vger.kernel.org Signed-off-by: Yunpeng Tian Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/udf/inode.c | 43 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 2f04c4f0e1b85..49673b555c624 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1336,6 +1336,26 @@ int udf_setsize(struct inode *inode, loff_t newsize) return err; } +/* + * Verify validity of struct deviceSpec on disk. udf_get_extendedattr() has + * already verified the generic header and made sure attribute fits in the + * inode so we just have to make sure attribute space is large enough for + * deviceSpec struct and required impUse information. + */ +static bool udf_device_spec_valid(struct deviceSpec *dsea) +{ + u32 attr_length, imp_use_length; + + attr_length = le32_to_cpu(dsea->attrLength); + imp_use_length = le32_to_cpu(dsea->impUseLength); + if (attr_length < sizeof(struct deviceSpec) || + imp_use_length < sizeof(struct regid) || + imp_use_length > attr_length - sizeof(struct deviceSpec)) + return false; + + return true; +} + /* * Maximum length of linked list formed by ICB hierarchy. The chosen number is * arbitrary - just that we hopefully don't limit any real use of rewritten @@ -1654,13 +1674,12 @@ static int udf_read_inode(struct inode *inode, bool hidden_inode) if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { struct deviceSpec *dsea = (struct deviceSpec *)udf_get_extendedattr(inode, 12, 1); - if (dsea) { - init_special_inode(inode, inode->i_mode, + + if (!dsea || !udf_device_spec_valid(dsea)) + goto out; + init_special_inode(inode, inode->i_mode, MKDEV(le32_to_cpu(dsea->majorDeviceIdent), le32_to_cpu(dsea->minorDeviceIdent))); - /* Developer ID ??? */ - } else - goto out; } ret = 0; out: @@ -1757,6 +1776,7 @@ int udf_write_inode(struct inode *inode, struct writeback_control *wbc) struct udf_sb_info *sbi = UDF_SB(inode->i_sb); unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits; struct udf_inode_info *iinfo = UDF_I(inode); + int err; bh = sb_getblk(inode->i_sb, udf_get_lb_pblock(inode->i_sb, &iinfo->i_location, 0)); @@ -1821,6 +1841,10 @@ int udf_write_inode(struct inode *inode, struct writeback_control *wbc) udf_add_extendedattr(inode, sizeof(struct deviceSpec) + sizeof(struct regid), 12, 0x3); + if (!dsea) { + err = -ENOSPC; + goto out_unlock; + } dsea->attrType = cpu_to_le32(12); dsea->attrSubtype = 1; dsea->attrLength = cpu_to_le32( @@ -1828,6 +1852,10 @@ int udf_write_inode(struct inode *inode, struct writeback_control *wbc) sizeof(struct regid)); dsea->impUseLength = cpu_to_le32(sizeof(struct regid)); } + if (!udf_device_spec_valid(dsea)) { + err = -EFSCORRUPTED; + goto out_unlock; + } eid = (struct regid *)dsea->impUse; memset(eid, 0, sizeof(*eid)); strcpy(eid->ident, UDF_ID_DEVELOPER); @@ -1962,6 +1990,11 @@ int udf_write_inode(struct inode *inode, struct writeback_control *wbc) set_inode_metadata_writeback(inode); return 0; + +out_unlock: + unlock_buffer(bh); + brelse(bh); + return err; } struct inode *__udf_iget(struct super_block *sb, struct kernel_lb_addr *ino, -- 2.53.0