[PATCH AUTOSEL 4.14 66/69] hfs: do not free node before using
From: Sasha Levin <sashal@kernel.org>
Date: 2018-12-05 09:42:44
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), hfs filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Viacheslav Dubeyko, John Paul Adrian Glaubitz, Yangtao Li, Linus Torvalds
From: Pan Bian <redacted> [ Upstream commit ce96a407adef126870b3f4a1b73529dd8aa80f49 ] hfs_bmap_free() frees the node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees the node only when it is never again used. Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by: Pan Bian <redacted> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Ernesto A. Fernandez <redacted> Cc: Viacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/hfs/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index 374b5688e29e..9bdff5e40626 100644
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c@@ -329,13 +329,14 @@ void hfs_bmap_free(struct hfs_bnode *node) nidx -= len * 8; i = node->next; - hfs_bnode_put(node); if (!i) { /* panic */; pr_crit("unable to free bnode %u. bmap not found!\n", node->this); + hfs_bnode_put(node); return; } + hfs_bnode_put(node); node = hfs_bnode_find(tree, i); if (IS_ERR(node)) return;
--
2.17.1