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Commit f08721ee authored by Stian Skjelstad's avatar Stian Skjelstad Committed by Greg Kroah-Hartman
Browse files

udf_get_extendedattr() had no boundary checks. 

[ Upstream commit 58bc6d1be2f3b0ceecb6027dfa17513ec6aa2abb ]

When parsing the ExtendedAttr data, malicous or corrupt attribute length
could cause kernel hangs and buffer overruns in some special cases.

Link: https://lore.kernel.org/r/20210822093332.25234-1-stian.skjelstad@gmail.com


Signed-off-by: default avatarStian Skjelstad <stian.skjelstad@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 64dd1fbb

fs/udf/misc.c

+11 −2
Original line number Diff line number Diff line
@@ -173,13 +173,22 @@ struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, 
		else

			offset = le32_to_cpu(eahd->appAttrLocation);



		while (offset < iinfo->i_lenEAttr) {

		while (offset + sizeof(*gaf) < iinfo->i_lenEAttr) {

			uint32_t attrLength;



			gaf = (struct genericFormat *)&ea[offset];

			attrLength = le32_to_cpu(gaf->attrLength);



			/* Detect undersized elements and buffer overflows */

			if ((attrLength < sizeof(*gaf)) ||

			    (attrLength > (iinfo->i_lenEAttr - offset)))

				break;



			if (le32_to_cpu(gaf->attrType) == type &&

					gaf->attrSubtype == subtype)

				return gaf;

			else

				offset += le32_to_cpu(gaf->attrLength);

				offset += attrLength;

		}

	}