From e4b963e9ae98a1c7522e97eec7015d33f7eb8ab4 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 26 Feb 2018 22:43:18 -0600 Subject: [PATCH] xfs: btree format ifork loader should check for zero numrecs Source kernel commit: 55e45429ce3e4ac9dd2bf4937b1a499a69ccc4ca A btree format inode fork with zero records makes no sense, so reject it if we see it, or else we can miscalculate memory allocations. Found by zeroes fuzzing {a,u3}.bmbt.numrecs in xfs/{374,378,412} with KASAN. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster Signed-off-by: Eric Sandeen --- libxfs/xfs_inode_fork.c | 1 + 1 file changed, 1 insertion(+) diff --git a/libxfs/xfs_inode_fork.c b/libxfs/xfs_inode_fork.c index 750d339e7..d75db5bdb 100644 --- a/libxfs/xfs_inode_fork.c +++ b/libxfs/xfs_inode_fork.c @@ -295,6 +295,7 @@ xfs_iformat_btree( */ if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <= XFS_IFORK_MAXEXT(ip, whichfork) || + nrecs == 0 || XFS_BMDR_SPACE_CALC(nrecs) > XFS_DFORK_SIZE(dip, mp, whichfork) || XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) || -- 2.47.2