From 8a6453a89dc10269adb1fc0cd0ceba928d557c21 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 13 Jan 2020 16:33:46 -0800 Subject: xfs: check log iovec size to make sure it's plausibly a buffer log format When log recovery is processing buffer log items, we should check that the incoming iovec actually describes a region of memory large enough to contain the log format and the dirty map. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_buf_item.c | 17 +++++++++++++++++ fs/xfs/xfs_buf_item.h | 1 + fs/xfs/xfs_log_recover.c | 6 ++++++ 3 files changed, 24 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index be691d1d9fad..5be8973a452c 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -27,6 +27,23 @@ static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip) STATIC void xfs_buf_do_callbacks(struct xfs_buf *bp); +/* Is this log iovec plausibly large enough to contain the buffer log format? */ +bool +xfs_buf_log_check_iovec( + struct xfs_log_iovec *iovec) +{ + struct xfs_buf_log_format *blfp = iovec->i_addr; + char *bmp_end; + char *item_end; + + if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->i_len) + return false; + + item_end = (char *)iovec->i_addr + iovec->i_len; + bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size]; + return bmp_end <= item_end; +} + static inline int xfs_buf_log_format_size( struct xfs_buf_log_format *blfp) diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h index 4a054b11011a..30114b510332 100644 --- a/fs/xfs/xfs_buf_item.h +++ b/fs/xfs/xfs_buf_item.h @@ -61,6 +61,7 @@ void xfs_buf_iodone_callbacks(struct xfs_buf *); void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *); bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *, struct list_head *); +bool xfs_buf_log_check_iovec(struct xfs_log_iovec *iovec); extern kmem_zone_t *xfs_buf_item_zone; diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 99ec3fba4548..0d683fb96396 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -1934,6 +1934,12 @@ xlog_recover_buffer_pass1( struct list_head *bucket; struct xfs_buf_cancel *bcp; + if (!xfs_buf_log_check_iovec(&item->ri_buf[0])) { + xfs_err(log->l_mp, "bad buffer log item size (%d)", + item->ri_buf[0].i_len); + return -EFSCORRUPTED; + } + /* * If this isn't a cancel buffer item, then just return. */ -- cgit