From ed150e1a5cf20c04cf0b2d2c34e498fc1d6519be Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 26 Aug 2016 15:58:40 +1000 Subject: xfs: don't perform lookups on zero-height btrees If the caller passes in a cursor to a zero-height btree (which is impossible), we never set block to anything but NULL, which causes the later dereference of it to crash. Instead, just return -EFSCORRUPTED. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_btree.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/xfs/libxfs/xfs_btree.c') diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index b5c213a051cd..33f14067c320 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -1814,6 +1814,10 @@ xfs_btree_lookup( XFS_BTREE_STATS_INC(cur, lookup); + /* No such thing as a zero-level tree. */ + if (cur->bc_nlevels == 0) + return -EFSCORRUPTED; + block = NULL; keyno = 0; -- cgit v1.2.3-70-g09d2 From 722278997bc964349e23e7061d541f8df3133a04 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 26 Aug 2016 15:59:50 +1000 Subject: xfs: fix some key handling problems in _btree_simple_query_range We only need the record's high key for the first record that we look at; for all records, we /definitely/ need the regular record key. Therefore, fix how the simple range query function gets its keys. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/xfs/libxfs/xfs_btree.c') diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 33f14067c320..b70d9f918156 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -4563,10 +4563,10 @@ xfs_btree_simple_query_range( error = xfs_btree_get_rec(cur, &recp, &stat); if (error || !stat) break; - cur->bc_ops->init_high_key_from_rec(&rec_key, recp); /* Skip if high_key(rec) < low_key. */ if (firstrec) { + cur->bc_ops->init_high_key_from_rec(&rec_key, recp); firstrec = false; diff = cur->bc_ops->diff_two_keys(cur, low_key, &rec_key); @@ -4575,6 +4575,7 @@ xfs_btree_simple_query_range( } /* Stop if high_key < low_key(rec). */ + cur->bc_ops->init_key_from_rec(&rec_key, recp); diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key); if (diff > 0) break; -- cgit v1.2.3-70-g09d2 From 5b5c2dbd3c9bcfa89fba9709c12ecc0a445c6e40 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 26 Aug 2016 16:00:10 +1000 Subject: xfs: simple btree query range should look right if LE lookup fails If the initial LOOKUP_LE in the simple query range fails to find anything, we should attempt to increment the btree cursor to see if there actually /are/ records for what we're trying to find. Without this patch, a bnobt range query of (0, $agsize) returns no results because the leftmost record never has a startblock of zero. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_btree.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/xfs/libxfs/xfs_btree.c') diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index b70d9f918156..08569792fe20 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -4558,6 +4558,13 @@ xfs_btree_simple_query_range( if (error) goto out; + /* Nothing? See if there's anything to the right. */ + if (!stat) { + error = xfs_btree_increment(cur, 0, &stat); + if (error) + goto out; + } + while (stat) { /* Find the record. */ error = xfs_btree_get_rec(cur, &recp, &stat); -- cgit v1.2.3-70-g09d2