Re: [syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xlog_cksum

[Edward Adam Davis]

#syz test

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index f8851ff835de..160eb6738c8c 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1581,8 +1581,12 @@ xlog_cksum(
 		union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
 		int		i;
 		int		xheads;
+		int		tail_xhead_len;
 
 		xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
+		tail_xhead_len = size % XLOG_HEADER_CYCLE_SIZE;
+		if (sizeof(struct xlog_rec_ext_header) > tail_xhead_len)
+			xheads -= 1;
 
 		for (i = 1; i < xheads; i++) {
 			crc = crc32c(crc, &xhdr[i].hic_xheader,