From 2e616d9f9ce8d469db4cd0a019cdc2ff3feab577 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 28 Jul 2019 21:12:32 -0700 Subject: [PATCH 1/2] xfs: fix stack contents leakage in the v1 inumber ioctls Explicitly initialize the onstack structures to zero so we don't leak kernel memory into userspace when converting the in-core inumbers structure to the v1 inogrp ioctl structure. Add a comment about why we have to use memset to ensure that the padding holes in the structures are set to zero. Fixes: 5f19c7fc6873351 ("xfs: introduce v5 inode group structure") Reported-by: Dan Carpenter Signed-off-by: Darrick J. Wong Reviewed-by: Eric Sandeen --- fs/xfs/xfs_itable.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c index a8a06bb78ea8..f5c955d35be4 100644 --- a/fs/xfs/xfs_itable.c +++ b/fs/xfs/xfs_itable.c @@ -272,6 +272,7 @@ xfs_bulkstat_to_bstat( struct xfs_bstat *bs1, const struct xfs_bulkstat *bstat) { + /* memset is needed here because of padding holes in the structure. */ memset(bs1, 0, sizeof(struct xfs_bstat)); bs1->bs_ino = bstat->bs_ino; bs1->bs_mode = bstat->bs_mode; @@ -388,6 +389,8 @@ xfs_inumbers_to_inogrp( struct xfs_inogrp *ig1, const struct xfs_inumbers *ig) { + /* memset is needed here because of padding holes in the structure. */ + memset(ig1, 0, sizeof(struct xfs_inogrp)); ig1->xi_startino = ig->xi_startino; ig1->xi_alloccount = ig->xi_alloccount; ig1->xi_allocmask = ig->xi_allocmask; From afa1d96d1430c2138c545fb76e6dcb21222098d4 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Tue, 30 Jul 2019 11:28:20 -0700 Subject: [PATCH 2/2] xfs: Fix possible null-pointer dereferences in xchk_da_btree_block_check_sibling() In xchk_da_btree_block_check_sibling(), there is an if statement on line 274 to check whether ds->state->altpath.blk[level].bp is NULL: if (ds->state->altpath.blk[level].bp) When ds->state->altpath.blk[level].bp is NULL, it is used on line 281: xfs_trans_brelse(..., ds->state->altpath.blk[level].bp); struct xfs_buf_log_item *bip = bp->b_log_item; ASSERT(bp->b_transp == tp); Thus, possible null-pointer dereferences may occur. To fix these bugs, ds->state->altpath.blk[level].bp is checked before being used. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/scrub/dabtree.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c index 94c4f1de1922..77ff9f97bcda 100644 --- a/fs/xfs/scrub/dabtree.c +++ b/fs/xfs/scrub/dabtree.c @@ -278,7 +278,11 @@ xchk_da_btree_block_check_sibling( /* Compare upper level pointer to sibling pointer. */ if (ds->state->altpath.blk[level].blkno != sibling) xchk_da_set_corrupt(ds, level); - xfs_trans_brelse(ds->dargs.trans, ds->state->altpath.blk[level].bp); + if (ds->state->altpath.blk[level].bp) { + xfs_trans_brelse(ds->dargs.trans, + ds->state->altpath.blk[level].bp); + ds->state->altpath.blk[level].bp = NULL; + } out: return error; }